tag:blogger.com,1999:blog-14179175705752605372024-03-05T16:16:37.368+05:30Tech That!First hand and raw information on technology & changes!Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.comBlogger47125tag:blogger.com,1999:blog-1417917570575260537.post-57948787110694373562009-03-24T11:46:00.002+05:302009-03-24T12:06:01.482+05:30Blu-ray Technology<span style="font-weight: bold;">What is Blu-ray?<br /></span>Blu-ray, also known as Blu-ray Disc (BD) is the name of a next-generation optical disc format. The format was developed to enable recording, rewriting and playback of high-definition video (HD), as well as storing large amounts of data. The format offers more than five times the storage capacity of traditional DVDs and can hold up to 25GB on a single-layer disc and 50GB on a dual-layer disc. For more general information about Blu-ray, please see our What is Blu-ray? section.<br /><br /><span style="font-weight: bold;">Why the name Blu-ray?</span><br />The name Blu-ray is derived from the underlying technology, which utilizes a blue-violet laser to read and write data. The name is a combination of "Blue" (blue-violet laser) and "Ray" (optical ray). According to the Blu-ray Disc Association the spelling of "Blu-ray" is not a mistake, the character "e" was intentionally left out so the term could be registered as a trademark.<br />The correct full name is Blu-ray Disc, not Blu-ray Disk (incorrect spelling) The correct shortened name is Blu-ray, not Blu-Ray (incorrect capitalization) or Blue-ray (incorrect spelling) The correct abbreviation is BD, not BR or BRD (wrong abbreviation)<br /><br /><span style="font-weight: bold;">Who developed Blu-ray?</span><br />The Blu-ray Disc format was developed by the Blu-ray Disc Association (BDA), a group of leading consumer electronics, personal computer and media manufacturers, with more than 170 member companies from all over the world. The Board of Directors currently consists of:<br />Apple Computer, Inc.<br />Dell Inc.<br />Hewlett Packard Company<br />Hitachi, Ltd.<br />LG Electronics Inc.<br />Matsushita Electric Industrial Co., Ltd.<br />Mitsubishi Electric Corporation<br />Pioneer Corporation<br />Royal Philips Electronics<br />Samsung Electronics Co., Ltd.<br />Sharp Corporation<br />Sony Corporation<br />TDK Corporation<br />Thomson Multimedia<br />Twentieth Century Fox<br />Walt Disney Pictures<br />Warner Bros. Entertainment<br /><br /><span style="font-weight: bold;">What Blu-ray formats are planned?</span><br />As with conventional CDs and DVDs, Blu-ray plans to provide a wide range of formats including ROM/R/RW. The following formats are part of the Blu-ray Disc specification:<br /><br />BD-ROM - read-only format for distribution of HD movies, games, software, etc.<br />BD-R - recordable format for HD video recording and PC data storage.<br />BD-RE - rewritable format for HD video recording and PC data storage.<br /><br />There's also plans for a BD/DVD hybrid format, which combines Blu-ray and DVD on the same disc so that it can be played in both Blu-ray players and DVD players.<br /><br /><span style="font-weight: bold;">How much data can you fit on a Blu-ray disc?<br /></span>A single-layer disc can hold 25GB.<br />A dual-layer disc can hold 50GB.<br /><br />To ensure that the Blu-ray Disc format is easily extendable (future-proof) it also includes support for multi-layer discs, which should allow the storage capacity to be increased to 100GB-200GB (25GB per layer) in the future simply by adding more layers to the discs.<br /><br /><span style="font-weight: bold;">How much video can you fit on a Blu-ray disc?<br /></span>Over 9 hours of high-definition (HD) video on a 50GB disc.<br />About 23 hours of standard-definition (SD) video on a 50GB disc.<br /><br /><span style="font-weight: bold;">How fast can you read/write data on a Blu-ray disc?<br /></span>According to the Blu-ray Disc specification, 1x speed is defined as 36Mbps. However, as BD-ROM movies will require a 54Mbps data transfer rate the minimum speed we're expecting to see is 2x (72Mbps). Blu-ray also has the potential for much higher speeds, as a result of the larger numerical aperture (NA) adopted by Blu-ray Disc. The large NA value effectively means that Blu-ray will require less recording power and lower disc rotation speed than DVD and HD-DVD to achieve the same data transfer rate. While the media itself limited the recording speed in the past, the only limiting factor for Blu-ray is the capacity of the hardware. If we assume a maximum disc rotation speed of 10,000 RPM, then 12x at the outer diameter should be possible (about 400Mbps). This is why the Blu-ray Disc Association (BDA) already has plans to raise the speed to 8x (288Mbps) or more in the future.<br /><br /><span style="font-weight: bold;">What video codecs will Blu-ray support?</span><br />MPEG-2 - enhanced for HD, also used for playback of DVDs and HDTV recordings.<br />MPEG-4 AVC - part of the MPEG-4 standard also known as H.264 (High Profile and Main Profile).<br />SMPTE VC-1 - standard based on Microsoft's Windows Media Video (WMV) technology.<br /><br />Please note that this simply means that all Blu-ray players and recorders will have to support playback of these video codecs, it will still be up to the movie studios to decide which video codec(s) they use for their releases.<br /><br /><span style="font-weight: bold;">What audio codecs will Blu-ray support?</span><br />Linear PCM (LPCM) - offers up to 8 channels of uncompressed audio. Dolby Digital (DD) - format used for DVDs also known as AC3, offers 5.1-channel surround sound. Dolby Digital Plus (DD+) - extension of DD, offers increased bitrates and 7.1-channel surround sound. Dolby TrueHD - extension of MLP Lossless, offers lossless encoding of up to 8 channels of audio. DTS Digital Surround - format used for DVDs, offers 5.1-channel surround sound. DTS-HD - extension of DTS, offers increased bitrates and up to 8 channels of audio.<br /><br />Please note that this simply means that all Blu-ray players and recorders will have to support playback of these audio codecs, it will still be up to the movie studios to decide which audio codec(s) they use for their releases.<br /><br /><span style="font-weight: bold;">Will Blu-ray discs require a cartridge?</span><br />No, the development of new low cost hard-coating technologies has made the cartridge obsolete. Blu-ray will instead rely on hard-coating for protection, which when applied will make the discs even more resistant to scratches and fingerprints than today's DVDs, while still preserving the same look and feel. Blu-ray also adopts a new error correction system which is more robust and efficient than the one used for DVDs.<br /><br /><span style="font-weight: bold;">Will Blu-ray require an Internet connection?</span><br />No, you will not need an Internet connection for basic playback of Blu-ray movies. The Internet connection will only be needed for value-added features such as downloading new extras, watching recent movie trailers, web browsing, etc. It will also be required to authorize managed copies of Blu-ray movies that can be transferred over a home network.<br /><br /><span style="font-weight: bold;">Will Blu-ray down-convert analog outputs?</span><br />No, Blu-ray players will not down-convert the analog output signal unless the video contains something called an Image Constraint Token (ICT). This feature is not part of the Blu-ray Disc spec, but of the AACS copy-protection system also adopted by HD-DVD. In the end it will be up to each movie studio to decide if they want to use this "feature" on their releases or not. The good news is that Sony, Disney, Fox, Paramount, MGM and Universal have already stated that they have no intention of using this feature. The other studios, which have yet to announce their plans, will most likely follow suit to avoid getting bad publicity. If any of the studios still decide to use ICT they will have to state this on the cover of their movies, so you should have no problem avoiding these titles.<br /><br /><span style="font-weight: bold;">Will Blu-ray support mandatory managed copy?</span><br />Yes, mandatory managed copy (MMC) will be part of the Blu-ray format. This feature will enable consumers to make legal copies of their Blu-ray movies that can be transferred over a home network. Please note that "mandatory" refers to the movies having to offer this capability, while it will be up to each hardware manufacturer to decide if they want to support this feature.<br /><br /><span style="font-weight: bold;">When will I be able to buy Blu-ray products?</span><br />If you live in the US, you will most likely have to wait until June 25, 2006 when Samsung will introduce their Blu-ray player (was recently pushed back from May 23, 2006). Pioneer and Sony plan to introduce their respective Blu-ray players in July. While we've heard very little about the launch plans for the European market, we expect it to follow shortly after the US (some products might launch earlier).<br /><br /><span style="font-weight: bold;">What will Blu-ray products cost?</span><br />As with any new technology the first generation of products will likely be quite expensive due to low production volumes. However, this shouldn't be a problem for long as there is a wide range of Blu-ray related products ( players, recorders, drives, writers, media, etc) planned, which should help drive up production volumes and lower overall production costs. Once mass production of components for Blu-ray products begins the prices are expected to fall quickly.<br />According to the Blu-ray Disc Association, the overall cost of manufacturing Blu-ray Disc media will in the end be no more expensive than producing a DVD. The reduced injection molding costs (one molding machine instead of two, no birefringence problems) offset the additional cost of applying the cover layer and low cost hard-coat, while the techniques used for applying the recording layer remain the same. As production volumes increase the production costs should fall and eventually be comparable to DVDs.Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com504tag:blogger.com,1999:blog-1417917570575260537.post-38269452027469546082008-06-30T11:46:00.002+05:302008-06-30T11:58:00.502+05:30The Other Microsoft Retirement: Your XP!Park Forest, IL—(ENEWSPF)— With all the hoopla over Bill Gates’ retirement from Microsoft, talk of Windows XP retiring has somehow slipped under most people’s radar.<br /><br />On June 30, 2008, Microsoft will officially stop producing Windows XP. What that means is that computer manufacturers and software suppliers will no longer be able to buy XP from Microsoft. What does that mean to those of us who are still running XP?<br /><br />Nothing.<br /><br />The world is not going to stop, at least on your computers anyway. You will still be able to get updates, and all of your applications will continue to work just fine.<br />Microsoft will continue to support XP untill 2014. See <a href="http://www.microsoft.com/windows/products/windowsxp/future.mspx">The facts about the future</a> at Microsoft.com for detailed information.<br />In truth, this was supposed to happen last year, but the cry from the masses paused the executioner to delay the imminent death of XP for one year.<br />We have seen this before. It happened to Windows 95, it happened to Windows 98, Windows 2000, ME, and now XP. In fact Windows 98 just stopped getting update support 2 years ago.<br />There are two reasons Microsoft retires an older operating system.<br /><br /><ol><li>It gets cumbersome to continue to make repairs updates on a technology that was<br />not meant to run some of the newest hardware and software. </li><li>Microsoft wants you to buy and use its latest operating system, in this case Vista. </li></ol><p>Let me make one thing clear, to those of you that are “Still” running Windows 98, Vista will not run on that computer. This may also be the case for many of you that are running XP. Looking at Dell’s Business sales from last year, 75% of businesses ordered their “Vista capable” systems with Windows XP.<br />The retail side was flipped, possible because retail was not offered a choice. 75% of retail customers “got” Vista on their systems. It will be interesting to see this year’s percentages. Based on my personal experience, corporations are “still” ordering and running XP on their desktops and workplaces.<br />Many programmers have not moved or tested their applications to run with Vista.<br />Vista, for many of you, will require a new system to handle Vista’s “Heavy Resource” requirement. This has also been the “corporate” reason to keep XP. (If I get you a new Vista Computer then I must get one for everyone!)<br />It is duly noted that there is no upgrade path from Windows 2000 or lower operating system to Vista. In plain English, if you upgrade a computer that is not XP to Vista, you must engage in a total wipe of you hard drive, reinstalling your applications and your data.<br />So, if you are not on XP, you’d better move your buns now.<br />But XP is being pulled you say. Suppliers and Manufactures will continue to “offer” XP as long as they have supplies. Dell will continue to offer XP, with a $50 surcharge, to some systems that ore ordered. HP, Gateway and Lenova are also offering XP as long as they have supply. So, when the supply runs out, XP runs out.<br />Microsoft is also in a tough place. Vista’s replacement is due out by 2010. Acceptance of Vista has not been really what Microsoft expected. Businesses have not embraced it and programmers have not adapted to it.<br />Windows 7, as the next Windows is now called, will start showing up in some beta form by this time next year. By the end of 2009, I believe some manufactures will be offering systems with Windows 7, or whatever the pet name will be by then.<br />Some of this may require new hardware, and I truly hope by then there will be new software to accommodate it.<br />So what do we do now? First, move on. If you want your Windows XP system to last you for awhile (3-5 years), here is what you need to do:<br /></p><ol><li>Get any and all updates your operating system needs. Yes, turn on Windows Update and do it. Any security patches and performance enhancements will keep your OS compatible with new applications and hardware coming down the pipe. </li><li>Apply Service Pack 3 for XP. This not only gets you updated but many people have discovered a performance bump after it is applied. </li><li>Upgrade your hardware to the max. Memory, Storage and even Video. This may be the last opportunity you have, as with many XP systems the hardware is dated and components are becoming harder to get. So unless your computer is less than 2 years old, your upgrades are starting to get harder to find if not already drying up stock in suppliers inventories. </li></ol><p>Now is the time for Microsoft to step up also. As Larry Dingman wrote in his article<a href="http://blogs.zdnet.com/BTL/?p=9103"> XP era ends: Will Vista step up?</a>, Microsoft will have to step up and ensure compatibility and get better tools for developers.<br />Microsoft will allow some system builders to offer XP Home on “Low End “ systems for a while, but it’s time to quit your whining and moaning, start saving up for your Vista, or Windows 7 system, and just get ready to change.<br />Maybe 6 years from now we will be writing this column and the XP people will be the 98’s of the day.<br /></p><p>Good Luck</p>Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com1tag:blogger.com,1999:blog-1417917570575260537.post-7867643804796461942007-07-16T09:20:00.000+05:302007-07-17T09:41:12.756+05:30How not to get hackedIt's important to know how not to get hacked. The following details the layers of security you can place on your wireless network, as well as the effectiveness of each layer.<br />In some ways, securing a network is like the security on your home:<br /><ul><li><span style="font-weight: bold;">Leave the front door wide open.</span> Seen by curious honest people and criminals alike as an open invitation to enter. See, it even says ‘Welcome’ on the doormat!</li><li><span style="font-weight: bold;">Shut the front door. </span>This will keep out an honest person, but a crook wouldn’t be deterred, as they’ll walk right up and try the handle.</li><li><span style="font-weight: bold;">Lock the front door. </span>This will again keep out the opportunist thief who will only try the door handle or climb in open a window to see if he can get it. Luckily most criminals fall into this category, so lock your door!</li><li><span style="font-weight: bold;">Bolt the door with deadbolts, bars on the windows, and alarms.</span> It takes a lot more to keep out the determined criminal who, with a little equipment and know-how, might pick the lock, disable your alarm, or break your whole door down!</li></ul>Wireless security falls into the same categories:<br /><br /><span style="font-weight: bold;">Leaving the door open: an open invitation</span><br /><ul><li>Broadcasting a default SSID</li><li>No MAC filtering</li><li>No encryption</li><li>DHCP switched on/No access controls</li></ul><span style="font-weight: bold;">Shutting the door:</span><br /><ul><li><span style="font-weight: bold;">Changing the SSID</span> (the name) of your network and disabling SSID broadcast. The determined hacker can discover this, so it merely protects you from the opportunist who’s in a hurry.</li><li><span style="font-weight: bold;">Disabling DHCP/Access Control.</span> This will not stop a hacker with even minimal knowledge, as there are many tools which will sniff out available IP addresses on your network</li><li><span style="font-weight: bold;">MAC address filtering.</span> A hacker with only a little know-how will be able to clone your MAC address--and see everything you see on your network.</li></ul><span style="font-weight: bold;">Locking the door</span><br /><ul><li>WEP: Wireless Encryption Protocol can be hacked in seconds using free tools that are widely available.</li></ul><span style="font-weight: bold;">Bolting the door<br /><br /></span><span style="font-weight: bold;">WPA: </span>A randomized pre-shared key of at least 10 characters would take half-a-million years to crack. More info about this<a href="http://blogs.zdnet.com/Ou/?p=127"> here</a>. (Note: A random key means that it shouldn’t be a word that exists in any dictionary (hackers have extensive dictionaries that include all common passwords, English words, nicknames, and misspellings of words. This is called a “dictionary attack.”) A random key is a meaningless mix of lower- and uppercase letters and numbers, and sometimes special characters like punctuation, depending on whether your router supports it). If you’re not sure how to get a random key, you can generate a simple WPA key online on <a href="http://www.kingsley-hughes.com/pc-zone/security/wpa.php">this Web site</a> or a more complex one <a href="http://darkvoice.dyndns.org/wlankeygen/">here</a>. You can also get software that will generate a key for you (type “software generate wpa key” into your favorite search engine).<br /><br />It’s best to build up each type of security in layers, checking that all devices can connect and communicate at each step before adding another layer. Make sure you read your router’s manual to ensure you’re storing the settings correctly (some routers require you to save the settings each time you make a change or the changes will be lost).Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com1tag:blogger.com,1999:blog-1417917570575260537.post-46701578060891881872007-06-15T11:28:00.000+05:302007-06-15T11:35:54.613+05:30Firewall<img title="Firewall" style="margin: 0px 0px 10px 10px; float: right;" src="http://img160.imageshack.us/img160/6772/firewallnew168457nu.gif" border="0" /> <strong>What is a firewall?</strong><br />A firewall protects networked computers from intentional hostile intrusion that could compromise confidentiality or result in data corruption or denial of service. It may be a hardware device running on a secure host computer. In either case, it must have at least two network interfaces, one for the network it is intended to protect, and one for the network it is exposed to. A firewall sits at the junction point or gateway between the two networks, usually a private network and a public network such as the Internet. The earliest firewalls were simply routers. The term firewall comes from the fact that by segmenting a network into different physical subnetworks, they limited the damage that could spread from one subnet to another just like firedoors or firewalls. <p></p><p><strong>What does a firewall do?</strong><br />A firewall examines all traffic routed between the two networks to see if it meets certain criteria. If it does, it is routed between the networks, otherwise it is stopped. A firewall filters both inbound and outbound traffic. It can also manage public access to private networked resources such as host applications. It can be used to log all attempts to enter the private network and trigger alarms when hostile or unauthorized entry is attempted. Firewalls can filter packets based on their source and destination addresses and port numbers. This is known as address filtering. Firewalls can also filter specific types of network traffic. This is also known as protocol filtering because the decision to forward or reject traffic is dependant upon the protocol used, for example <strong>HTTP</strong>, <strong>ftp</strong> or <strong>telnet</strong>. Firewalls can also filter traffic by packet attribute or state. </p><p><strong>What can't a firewall do?</strong><br />A firewall cannot prevent individual users with modems from dialling into or out of the network, bypassing the firewall altogether. Employee misconduct or carelessness cannot be controlled by firewalls. Policies involving the use and misuse of passwords and user accounts must be strictly enforced. These are management issues that should be raised during the planning of any security policy but that cannot be solved with firewalls alone.<br />The arrest of the Phonemasters cracker ring brought these security issues to light. Although they were accused of breaking into information systems run by AT&T Corp., British Telecommunications Inc., GTE Corp., MCI WorldCom, Southwestern Bell, and Sprint Corp, the group did not use any high tech methods such as <strong>IP spoofing</strong> . They used a combination of social engineering and dumpster diving. Social engineering involves skills not unlike those of a confidence trickster. People are tricked into revealing sensitive information. Dumpster diving or garbology, as the name suggests, is just plain old looking through company trash. Firewalls cannot be effective against either of these techniques. </p><p><strong>Who needs a firewall?</strong><br />Anyone who is responsible for a private network that is connected to a public network needs firewall protection. Furthermore, anyone who connects so much as a single computer to the Internet via modem should have personal firewall software. Many dial-up Internet users believe that anonymity will protect them. They feel that no malicious intruder would be motivated to break into their computer. Dial up users who have been victims of malicious attacks and who have lost entire days of work, perhaps having to reinstall their operating system, know that this is not true. Irresponsible pranksters can use automated robots to scan random IP addresses and attack whenever the opportunity presents itself. </p><p><strong>How does a firewall work?</strong><br />There are two access denial methodologies used by firewalls. A firewall may allow all traffic through unless it meets certain criteria, or it may deny all traffic unless it meets certain criteria . The type of criteria used to determine whether traffic should be allowed through varies from one type of firewall to another. Firewalls may be concerned with the type of traffic, or with source or destination addresses and ports. They may also use complex rule bases that analyse the application data to determine if the traffic should be allowed through. How a firewall determines what traffic to let through depends on which network layer it operates at. A discussion on network layers and architecture follows. </p><p><strong>What are the OSI and TCP/IP Network models?</strong><br />To understand how firewalls work it helps to understand how the different layers of a network interact. Network architecture is designed around a seven layer model. Each layer has its own set of responsibilities, and handles them in a well-defined manner. This enables networks to mix and match network protocols and physical supports. In a given network, a single protocol can travel over more than one physical support (layer one) because the physical layer has been dissociated from the protocol layers (layers three to seven). Similarly, a single physical cable can carry more than one protocol. The <strong>TCP</strong>/<strong>IP</strong> model is older than the <strong>OSI</strong> industry standard model which is why it does not comply in every respect. The first four layers are so closely analogous to OSI layers however that interoperability is a day to day reality.<br />Firewalls operate at different layers to use different criteria to restrict traffic. The lowest layer at which a firewall can work is layer three. In the OSI model this is the network layer. In TCP/IP it is the Internet Protocol layer. This layer is concerned with routing packets to their destination. At this layer a firewall can determine whether a packet is from a trusted source, but cannot be concerned with what it contains or what other packets it is associated with. Firewalls that operate at the transport layer know a little more about a packet, and are able to grant or deny access depending on more sophisticated criteria. At the application level, firewalls know a great deal about what is going on and can be very selective in granting access.<br />It would appear then, that firewalls functioning at a higher level in the stack must be superior in every respect. This is not necessarily the case. The lower in the stack the packet is intercepted, the more secure the firewall. If the intruder cannot get past level three, it is impossible to gain control of the operating system.<br />Professional firewall products catch each network packet before the operating system does, thus, there is no direct path from the Internet to the operating system's TCP/IP stack. It is therefore very difficult for an intruder to gain control of the firewall host computer then "open the doors" from the inside.<br />According To Byte Magazine, traditional firewall technology is susceptible to misconfiguration on non-hardened OSes. More recently, however, "<u>...firewalls have moved down the protocol stack so far that the OS doesn't have to do much more than act as a bootstrap loader, file system and <strong>GUI</strong></u>". The author goes on to state that newer firewall code bypasses the operating system's IP layer altogether, never permitting "<u>potentially hostile traffic to make its way up the protocol stack to applications running on the system</u>". </p><p><strong>What different types of firewalls are there?</strong><br />Firewalls fall into four broad categories: packet filters, circuit level gateways, application level gateways and stateful multilayer inspection firewalls. Packet filtering firewalls work at the network level of the OSI model, or the IP layer of TCP/IP. They are usually part of a router. A router is a device that receives packets from one network and forwards them to another network. In a packet filtering firewall each packet is compared to a set of criteria before it is forwarded. Depending on the packet and the criteria, the firewall can drop the packet, forward it or send a message to the originator. Rules can include source and destination IP address, source and destination port number and protocol used. The advantage of packet filtering firewalls is their low cost and low impact on network performance. Most routers support packet filtering. Even if other firewalls are used, implementing packet filtering at the router level affords an initial degree of security at a low network layer. This type of firewall only works at the network layer however and does not support sophisticated rule based models . Network Address Translation (<strong>NAT</strong>) routers offer the advantages of packet filtering firewalls but can also hide the IP addresses of computers behind the firewall, and offer a level of circuit-based filtering.<br />Circuit level gateways work at the session layer of the OSI model, or the TCP layer of TCP/IP. They monitor TCP handshaking between packets to determine whether a requested session is legitimate. Information passed to remote computer through a circuit level gateway appears to have originated from the gateway. This is useful for hiding information about protected networks. Circuit level gateways are relatively inexpensive and have the advantage of hiding information about the private network they protect. On the other hand, they do not filter individual packets.<br />Application level gateways, also called proxies, are similar to circuit-level gateways except that they are application specific. They can filter packets at the application layer of the OSI model. Incoming or outgoing packets cannot access services for which there is no proxy. In plain terms, an application level gateway that is configured to be a web proxy will not allow any ftp, gopher, telnet or other traffic through. Because they examine packets at application layer, they can filter application specific commands such as http:post and get, etc. This cannot be accomplished with either packet filtering firewalls or circuit level neither of which know anything about the application level information. Application level gateways can also be used to log user activity and logins. They offer a high level of security, but have a significant impact on network performance. This is because of context switches that slow down network access dramatically. They are not transparent to end users and require manual configuration of each client computer.<br />Stateful multilayer inspection firewalls combine the aspects of the other three types of firewalls. They filter packets at the network layer, determine whether session packets are legitimate and evaluate contents of packets at the application layer. They allow direct connection between client and host, alleviating the problem caused by the lack of transparency of application level gateways. They rely on algorithms to recognize and process application layer data instead of running application specific proxies. Stateful multilayer inspection firewalls offer a high level of security, good performance and transparency to end users. They are expensive however, and due to their complexity are potentially less secure than simpler types of firewalls if not administered by highly competent personnel. </p><p><strong>Is a firewall sufficient to secure my network or do I need anything else?</strong><br />The firewall is an integral part of any security program, but it is not a security program in and of itself. Security involves data integrity (<u>has it been modified?</u>), service or application integrity (<u>is the service available, and is it performing to spec?</u>), data confidentiality (<u>has anyone seen it?</u>) and authentication (<u>are they really who they say they are?</u>). Firewalls only address the issues of data integrity, confidentiality and authentication of data that is behind the firewall. Any data that transits outside the firewall is subject to factors out of the control of the firewall. It is therefore necessary for an organization to have a well planned and strictly implemented security program that includes but is not limited to firewall protection. </p><p><strong>What is IP spoofing?</strong><br />Many firewalls examine the source IP addresses of packets to determine if they are legitimate. A firewall may be instructed to allow traffic through if it comes from a specific trusted host. A malicious cracker would then try to gain entry by "spoofing" the source IP address of packets sent to the firewall. If the firewall thought that the packets originated from a trusted host, it may let them through unless other criteria failed to be met. Of course the cracker would need to know a good deal about the firewall's rule base to exploit this kind of weakness. This reinforces the principle that technology alone will not solve all security problems. Responsible management of information is essential. One of Courtney's laws sums it up: "<u>There are management solutions to technical problems, but no technical solutions to management problems</u>".<br />An effective measure against IP spoofing is the use of a Virtual Private Network (<strong>VPN</strong>) protocol such as IPSec. This methodology involves encryption of the data in the packet as well as the source address. The VPN software or firmware decrypts the packet and the source address and performs a checksum. If either the data or the source address have been tampered with, the packet will be dropped. Without access to the encryption keys, a potential intruder would be unable to penetrate the firewall. </p><p><strong>Firewall related problems:</strong> </p><ul><li>Firewalls introduce problems of their own. Information security involves constraints, and users don't like this. It reminds them that Bad Things can and do happen. Firewalls restrict access to certain services. The vendors of information technology are constantly telling us "<u>anything, anywhere, any time</u>", and we believe them naively. Of course they forget to tell us we need to log in and out, to memorize our 27 different passwords, not to write them down on a sticky note on our computer screen and so on. </li><li>Firewalls can also constitute a traffic bottleneck. They concentrate security in one spot, aggravating the single point of failure phenomenon. The alternatives however are either no Internet access, or no security, neither of which are acceptable in most organizations. </li></ul><p><strong>Benefits of a firewall:</strong> </p><ul><li>Firewalls protect private local area networks from hostile intrusion from the Internet. Consequently, many <strong>LAN</strong>s are now connected to the Internet where Internet connectivity would otherwise have been too great a risk. </li><li>Firewalls allow network administrators to offer access to specific types of Internet services to selected LAN users. This selectivity is an essential part of any information management program, and involves not only protecting private information assets, but also knowing who has access to what. Privileges can be granted according to job description and need rather than on an all-or-nothing basis.</li></ul>Thanks <a href="mailto:ayub91@yahoo.com">Ayub</a> for sending me this post.Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com0tag:blogger.com,1999:blog-1417917570575260537.post-33350602868906512632007-06-11T09:55:00.000+05:302007-06-11T12:27:11.467+05:30Microsoft Excel formulasFollowing are the most asked questions of <a href="http://office.microsoft.com/en-us/excel/FX100487621033.aspx">microsoft excel</a>. I hope you'll find it worthwhile.<br /><strong></strong><br /><strong>Excel settings: </strong><br /><ul><li><strong>When I enter a value, it appears with two decimal places. For example, when I enter 154 it shows up as 1.54. What's wrong?</strong><br />Somehow Excel's fixed-decimal mode was turned on. To return to normal select <u>Tools</u> » <u>Options</u> » <u>Edit</u> » remove the <em>check mark</em> from the <u>Fixed decimal</u> option. </li><li><strong>Can I change the color of the worksheet tabs in my workbook?</strong><br />No. It would certainly be helpful to be able to color-code your worksheet tabs. Microsoft hasn't implemented this feature (please check this feature in <a href="http://officelive.microsoft.com/">Microsoft Office Live</a>. I heard its available in this new version of office, though not sure) which has been available in 1-2-3 and Quattro Pro for quite a while. </li><li><strong>I saved my workbook with a password, but Excel doesn't recognize it and won't let me open the file. Am I out of luck? </strong><br />Passwords are <u>case sensitive</u>. So if you originally entered your password as Xyzzy then typing xyzzy won't work. If you are entering the password correctly then it's time to start looking for a <u>password recovery utility</u>. Several utilities exist and some of them are free. <a href="http://www.google.com/ncr">Google search</a> for <u>Excel password recovery</u> and you'll find several products that will come to the <u>rescue</u>. These products might raise some alarms for the <em>security minded</em>.<br />Bottom line?<br />Excel password protection isn't as secure as you might expect. </li><li><strong>How can I increase the number of rows or columns in a worksheet?<br /></strong>Every workbook in Excel has <u>255 columns</u> and <u>65,526 rows</u>. These values are fixed and cannot be changed. If you need more rows use <a href="http://office.microsoft.com/access">Microsoft Access</a> or latest version of Excel also known as <a href="http://office.microsoft.com/en-us/excel/FX100487621033.aspx">Microsoft Excel Online</a>. </li></ul><p><strong>Formulas and Functions:</strong> </p><ul><li><strong>Is there a function that returns the name of the worksheet?</strong><br />Excel's CELL function comes close. The following formula displays the workbook's full path along with the worksheet name:<br />=CELL("filename")<br />For example this formula might return something like:<br /><u>C:\Windows\Desktop\[Budget.xls]Sheet2</u><br />Returning only the sheet name requires a more complex formula:<br />=MID(CELL("filename"), FIND("]",CELL("filename"))+1, LEN(CELL("filename"))-FIND("]", CELL("filename"))) </li><li><strong>I have a price list stored in a worksheet and I need to increase all prices by 5 percent. Can I do this without re-entering all the prices?</strong><br />Excel provides two ways <u>traditional technique</u> which goes something like this...<br />Insert or find a blank column near the prices.<br />In that column's first cell enter a formula to multiply the price in that row by 1.05.<br />Copy the formula down the column.<br />Then select and copy the entire column of formulas, select the original prices and choose Edit » Paste Special » select Values to overwrite the original prices with the formulas results.<br />And finally delete the column of formulas.<br />Another more efficient approach also uses the <u>Paste Special dialog box</u>.<br />To increase a range of values (prices in this example) by 5 percent enter 1.05 into any blank cell.<br />Select the cell and choose Edit » Copy.<br />Then select the range of values and choose Edit » Paste Special.<br />Choose the <u>Multiply option</u> and click OK.<br />Then delete the cell that contains the 1.05. </li><li><strong>I've created some clever formulas and I don't want anyone else to see them. Is it possible to hide the formulas but display the results?</strong><br /><br /><a href="http://www.flickr.com/photo_zoom.gne?id=540116860&size=o"><img src="http://img379.imageshack.us/img379/6158/123ng8.jpg" border="0" /></a><br /><br />Every cell has two key properties: locked and hidden.<br />A locked cell can't be changed and the contents of a hidden cell don't appear in the formula bar when the cell is selected.<br />By default every cell is locked and not hidden. But it's important to remember that these attributes have no effect unless the worksheet itself is protected.<br />To change the attributes select the appropriate cell or range and then choose Format » Cells » Protection » Locked or Hidden (or both).<br />Unlock cells that accept user input and lock formula and other cells that should stay unchanged (such as titles).<br />To prevent others from seeing your formulas lock and hide the formula cells. The results of the formulas will be visible but the formulas will not.<br /><br /><a href="http://www.flickr.com/photo_zoom.gne?id=540116864&size=o0"><img src="http://img264.imageshack.us/img264/971/124fx6.jpg" border="0" /></a><br /><br />To protect the worksheet choose Tools » Protection » Protect Sheet. Make sure the Contents box is checked. Enter a password to prevent others from unprotecting the sheet. <u>Locked cells</u> in a <u>protected sheet</u> cannot be edited and changes are disabled. </li><li><strong>Can I write a formula that returns the number of distinct entries in a range?</strong><br />Say we're hunting for a formula that, given the range 100, 99, 98, 100, 98, 100, 98, would return 3. This type of counting requires an array formula. For example counts the number of distinct entries in the range A1:D100.<br />=SUM(1/COUNTIF(A1:D100, A1:D100))<br />When you enter this formula you must press <u>Ctrl-Shift-Enter</u>.<br />Pressing only Enter will give you the wrong result.<br />Excel will place brackets around the formula to remind you that you've created an array formula.<br />The preceding formula works fine in many cases but it will return an error if the range contains any blank cells.<br />The formula below with Ctrl-Shift-Enter is more complex but it will handle a range that contains a blank cell.<br />=SUM(IF(COUNTIF(A1:D100,A1:D100)=0, "", 1/COUNTIF(A1:D100,A1:D100))) </li></ul><p>Thanks <a href="mailto:ayub91@yahoo.com">Ayub</a> for sending me this great finding. Also thanks <a href="http://www.imageshack.us/">Imageshack</a> for hosting the above images for free. </p>Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com19tag:blogger.com,1999:blog-1417917570575260537.post-25191137594511722652007-06-10T12:03:00.000+05:302007-06-12T20:30:08.610+05:30Excel Trickswriting this set of tricks I found <a href="http://www.google.com/search?hl=en&q=MS+Excel+tricks">more than 600</a> relevant <a href="http://en.wikipedia.org/wiki/Blog">blogs</a> and <a href="http://en.wikipedia.org/wiki/Website">sites</a> with the help of <a href="http://labs.google.com/suggest">Google</a>. Not all of them are different but some have incredible codes which empowers you to control Excel in very easy way and in full. Some of the codes and tricks are given below, I hope it will help you save your time and increase your productivity.<br /><strong><br />When I open a workbook Excel asks if I want to update the links. I've looked everywhere, and I can't find any links in my formulas!</strong><br /><ul><li>I've never known Excel to be wrong about identifying links, so there's an excellent chance your <em>workbook</em> does contain one or more links but they are probably not <u>formula links</u>. </li><li>If you have a chart in your workbook click each <em>data series</em> in the chart and examine the <u>Series formula</u> in the formula bar. If the formula refers to another workbook, you've identified the link. To eliminate it and move the chart's data into the current workbook and recreate your chart. If your workbook contains any <em>dialog sheets</em> then select each object in each dialog box and examine the formula bar. If any object contains a reference to another workbook just edit or delete that reference. And if these two approaches don't solve your problem simply follow the following steps... </li><li><em>Step 1:</em><br />Select Edit » Links. The link <em>dialog box</em> will appear.<br />(In some cases, this command is not available. If you can't select it just skip to step 4.) </li><li><em>Step 2:</em><br />Click the <u>Change Source button</u> and change the link to the active file. </li><li><em>Step 3:</em><br />Select Insert » Name » Define. Scroll down the list in the <u>Define Name dialog box</u> and examine the <u>Refers to</u> box. Delete names that refer to another workbook or that contain an <em>erroneous reference</em> (such as #REF!). This is the most common cause of <u>phantom links</u>. </li><li><em>Step 4:</em><br />Save your workbook. When you re-open it, Excel won't ask you to update links! Simple!! </li></ul><p><strong>How can I make text in a cell display in multiple lines?</strong><br />When entering text into the cell, press <u>Alt-Enter</u> to insert a <u>line break</u>.<br />When you do so, Excel will automatically apply text wrapping to the cell.<br />To <u>re-format</u> existing cells so they sport wrapped text, select the Cells and choose Format » Cells. On the <u>Alignment tab</u> select <u>Wrap text</u> and click OK. </p><p><strong>Sometimes my formulas do not get fully calculated. This often happens when I use custom functions created with Visual Basic.</strong><br /><a href="http://www.microsoft.com/">Microsoft</a> has acknowledged some problems with the <u>Excel calculation engine</u>. In order to be assured that all of your formulas have been calculated press <u>Ctrl-Alt-F9</u> to force a <em>complete recalculation</em>. </p><p><strong><u>Dates and times:</u></strong> </p><p><strong>How can I calculate the difference between two dates?</strong><br />Excel stores dates as serial numbers. The number 1 represents 1st January 1900, the number 2 represents 2nd January 1900 and so on. Formatting these numbers using a date format causes them to appear as actual dates. Therefore, if you have dates stored in two cells, you can simply create a formula that subtracts one from the other to get the number of intervening days. You'll want to make sure that the formula cell is formatted as a number, not a date. <u>DATEDIF</u> function which was not documented prior to <u>Excel 2000</u> returns the difference between two dates expressed in years, months or days.<br />Excel's DATEDIF function takes three arguments. Its syntax is:<br />=DATEDIF (start_date, end_date, units)<br />In the syntax start_date is a date or reference to a date... end_date is a date or reference to a date... and units is a one- or two-digit string (in double quotes) specifying the units for the difference between the two dates.<br />Acceptable values for the units argument are shown below... </p><ul><li>y returns the number of full years in the period. </li><li>m returns the number of full months in the period. </li><li>d returns the number of full days in the period. </li><li>md returns the number of full days in excess of the last full month. </li><li>ym returns the number of full months in excess of the last full year. </li><li>yd returns the number of full days in excess of the last full year.<br />For example, assume cells A1 and B1 contain dates. The formula below returns the number of full years between the dates (useful for calculating a person's age):<br />=DATEDIF(A1,B1,"y")<br />The formula below calculates the number of full months between the two dates:<br />=DATEDIF(A1,B1,"m") </li></ul><p><strong>I have a range of time values but when I try to sum them the total is never greater than 24 hours.</strong><br />When you add a range that contains time values, Excel ignores the hours that exceed 24. The solution is to use a custom number format. Activate the cell that contains your total time and then choose Format » Cells » Number tab. Choose Custom from the Category list and type [h]:mm into the box labeled Type. Using brackets around the hour portion of the format string tells Excel to display hours that exceed 24 hours. </p><p><strong>I have a worksheet that shows total hours and minutes worked along with the hourly pay rate. When I multiply these vales I don't get the result I'm looking for. What's wrong?</strong><br />Multiply the result by 24 for the number of hours in a day.<br />If cell A1 contains the number of hours worked (for example, 16:45, for 16 hours and 45 minutes) and cell B1 has the hourly rate then the formula below will calculate the total wages...<br />=A1*B1*24<br />Make sure the cell that contains the formula is formatted as a number and not as time. </p><p><strong>Is it possible to determine the day of the week for a particular date?</strong><br />Yes, assume that cell A1 contains a date value. The formula below uses the WEEKDAY function, which returns an integer between 1 and 7 (1 for Sunday, 2 for Monday, and so on).<br />=WEEKDAY(A1)<br />If you'd prefer to see words rather than integers please modify the formula as follows:<br />=CHOOSE(WEEKDAY(A1), "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday")<br />Another approach is activate the cell that contains your date and then choose Format » Cells » Number tab. Choose Custom from the Category list and type a custom number format string into the box labeled <u>Type</u>. The trick here is to use <u>dddd</u> as part of the format string.<br />For example, a format string of dddd mmmm d, yyyy will display the date and the day of the week, like this: Thursday November 23, 2000. </p><p><strong>I need to determine the difference between two times. If the difference is positive, it works fine. But Excel doesn't want to display negative time values. Why not?</strong><br />Excel stores dates and times as numeric values, so it should be possible to add or subtract one from the other. The problem occurs if you have a workbook containing only times and no dates. Subtracting one time from another doesn't always work. Negative time values appear as a series of pound signs, even though you've assigned the [h]:mm format to the cells. By default, Excel uses a date system that begins with January 1, 1900. A negative time value generates a date-time combination that falls before this date, which is invalid.<br />The solution is to use the 1904 date system. Select Tools » Options » Calculation tab and check the 1904 date system option to change the starting date to January 2, 1904. Your negative times will now be displayed correctly.<br /><em><u>Note:</u></em> If you use the 1904 date system, be careful when linking to date cells in other workbooks. If the linked workbook uses the 1900 date system, the dates retrieved by the links will be incorrect. </p><p><strong>How can I enter the current date into a cell so it doesn't change from day to day? When I use the NOW function it always shows the current date!</strong><br />The easiest way to enter the current date into a cell is to use the <strong>Ctrl-;</strong> key combination (press the Ctrl key and type a semicolon).<br />Similarly you can enter the current time by pressing <strong>Ctrl-Shift-;</strong> (press the Ctrl and Shift keys and type a semicolon). Both of these key combinations enter the information as a volatile value and not as a formula. </p><p><strong><u>Chart and printing:</u></strong> </p><p><strong>How can I print a workbook's full path in the header or footer? The Page Setup dialog box doesn't seem to offer the option.</strong><br /><br /><a href="http://www.flickr.com/photo_zoom.gne?id=540116858&size=o"><img src="http://img100.imageshack.us/img100/4087/440453444c273b160dfmur2.jpg" border="0" /></a><br /><br />Microsoft continues to ignore what must be thousands of requests for this feature. Although <a href="http://office.microsoft.com/word">Microsoft Word</a> offers this feature but Excel offers no direct way to print a workbook's full path in the header or footer. The only solution is to create a macro. The technique described below works with Excel 97 and later.<br />Press <u>Alt-F11</u> to activate the Visual Basic editor.<br />In the Project window, double-click the project that corresponds to your workbook. The project list will expand to show several objects.<br />Double-click the item labeled <u>Microsoft Excel Objects</u> and then double-click the object labeled <u>ThisWorkbook</u>.<br />Enter the following three lines of <strong>VBA code</strong> into the code module for the ThisWorkbook object (usually in the right pane of the window you're seeing at this point).<br /><br />Private Sub Workbook_BeforePrint (Cancel As Boolean)<br />ActiveSheet.PageSetup.LeftHeader = ThisWorkbook.FullName<br />End Sub<br />After inserting the code, press Alt-Q to return to Excel.<br /><br />This procedure will be executed before you print or preview your workbook. It simply inserts the workbook's path into the left header position. If you prefer to put the path in a different position, substitute any of the following for LeftHeader: CenterHeader, RightHeader, LeftFooter, CenterFooter or RightFooter. </p><p><strong>How can I save a chart as a GIF file?</strong><br />You can save your worksheet as an HTML file and Excel will automatically convert any charts to GIF files. If that seems like overkill you can write a simple macro that will do the job. Press <u>Alt-F11</u> to activate the <u>Visual Basic editor</u>. Select your workbook in the Projects window and choose Insert » Module to insert a new VBA module. Then type the following four-line procedure into the module...<br /><br />Sub SaveChartAsGIF ()<br />Fname = ThisWorkbook.Path & "\" &amp;amp;amp;amp;amp;amp; ActiveChart.Name & ".gif"<br />ActiveChart.Export FileName:=Fname, FilterName:="GIF"<br />End Sub<br /><br />After the macro is entered, reactivate Excel and click the chart to be saved.<br />Press <u>Alt-F8</u> to display the Macro dialog box.<br />Select the SaveChartAsGIF macro and click Run. The procedure uses the chart's name as the GIF file name, and the file is stored in the same directory as the workbook.<br />This simple macro does no error checking, so it will generate an error if a chart is not selected or if the workbook has not been saved. </p><p>The above information is freely available on the internet. <a href="http://www.blogger.com/ayub91@yahoo.com">Ayub</a>, <a href="mailto:umakant@gmail.com">Umakant</a> and some friends helped me finding related questions.<br />Thanks <a href="http://www.imageshack.us/">Imageshack</a> fo hosting the above image for free. Please use <a href="http://imageshack.us/">imageshack</a> for all your website picture hosting. </p>Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com2tag:blogger.com,1999:blog-1417917570575260537.post-67999097055115615452007-06-08T16:13:00.000+05:302007-06-09T10:17:22.566+05:30DHCP Complete<strong>What is DHCP?</strong><br />DHCP (Dynamic Host Configuration Protocol) is a protocol that lets <em>network administrators</em> manage centrally and automate the <em>assignment</em> of <em>IP</em> (Internet Protocol) configurations on a <u>computer network</u>. When using the Internet's set of <u>protocols</u> (TCP/IP), in order for a <em>computer system</em> to communicate to another computer system it needs a unique <u>IP address</u>. Without DHCP, the IP address must be entered manually at each computer system. DHCP lets a network administrator supervise and distribute IP addresses from a <em>central point</em>. The purpose of DHCP is to provide the automatic (dynamic) allocation of IP client configurations for a specific time period (lease period) and to eliminate the work necessary to administer a large <u>IP network</u>.<br /><br /><strong>Who created DHCP?</strong><br />DHCP was created by the Dynamic Host Configuration <em>Working Group</em> of the <u>Internet Engineering Task Force</u> (IETF) a volunteer organization which defines protocols for use on the Internet. Its definition is recorded in an Internet RFC (standard) and the <u>Internet Activities Board</u> (IAB) is asserting its status as to <em>Internet Standardization</em>.<br /><br /><strong>Why is DHCP important?</strong><br />When connected to a network, every computer must be assigned a <u>unique address</u>. However, when adding a machine to a network, the assignment and <u>configuration of network</u> (IP) addresses has required human action. The computer user had to request an address and then the administrator would manually configure the machine. Mistakes in the configuration process are easy for novices to make, and can cause difficulties for both the administrator making the error as well as neighbors on the network. Also, when mobile computer users travel between sites, they have had to relive this process for each different site from which they connected to a network. In order to simplify the process of adding machines to a network and assigning unique IP addresses manually, there is a need to automate the task. The introduction of DHCP alleviated the problems associated with manually assigning TCP/IP client addresses. Network administrators have quickly appreciated the importance, flexibility and ease-of-use offered in DHCP.<br /><br /><strong>How does DHCP work?</strong><br />When a client needs to start up TCP/IP operations, it <em>broadcasts a request</em> for address information. The DHCP server receives the request, assigns a new address for a specific time period (called a lease period) and sends it to the client together with the other required configuration information. This information is acknowledged by the client, and used to set up its configuration. The DHCP server will not re allocate the address during the lease period and will attempt to return the same address every time the client requests an address. The client may extend its lease with subsequent requests, and may send a message to the server before the lease expires telling it that it no longer needs the address so it can be released and assigned to another client on the network.<br /><br /><strong>What advantages does DHCP have over manual configuration methods?</strong><br />The use of DHCP is highly recommended and there are a number of obvious reasons why you should use it. As mentioned before, there are two ways you can configure client addresses on a computer network, either manually or automatically. Manual configuration requires the careful input of a unique IP address, <em>subnet mask</em>, default router address and a <em>Domain Name Server</em> address. In an ideal world, manually assigning client addresses should be relatively straight forward and error free. Unfortunately we do not live in an ideal world so computers are frequently moved and new systems get added to a network. Also if a major network resource, such as a router (which interconnects networks) changes network addresses, this could mean changing EVERY system's configuration. For a network administrator this process can be time consuming, tedious and error prone. Problems can occur when manually setting up your client machines, so if you have the option to set-up your client machines automatically, please do, as it will save you time and a lot of headaches. DHCP has several major advantages over manual configurations. Each computer gets its configuration from a "pool" of available numbers automatically for a specific time period (called a leasing period), meaning no wasted numbers. When a computer has finished with the address, it is released for another computer to use. Configuration information can be administered from a single point. Major network resource changes ( e.g. a router changing address), requires only the DHCP server be updated with the new information, rather than every system.<br /><br /><strong>Can DHCP provide support for mobile users?</strong><br />Yes. The benefits of dynamic addressing are especially helpful in mobile computing environments where users frequently change locations. Mobile users simply plug-in their laptop to the network, and receive their required configuration automatically. When moving to a different network using a DHCP server, then the configuration will be supplied by that network's server. No manual reconfiguration is required at all.<br /><br /><strong>Are DHCP servers easy to set-up and administer?</strong><br />DHCP Servers offer completely centralized management of all TCP/IP client configurations, including IP address, gateway address and DNS address. DHCP servers are easy to administer and can be set-up in just a few minutes. Client addresses are assigned automatically unlike static set-up which requires the manual input of client addresses which can be a time consuming and tedious task.<br /><br /><strong>Are there any limitations that I should be aware of?</strong><br />Some machines on your network need to be at fixed addresses, for example servers and routers. The DHCP server you choose should be capable of assigning pre-allocated addresses to these specific machines. You need to be able to assign a machine to run the DHCP server continually as it must be available at all times when clients need IP access. To avoid conflicts between addresses assigned by the DHCP server and those assigned manually, users should be discouraged, or preferably prevented, from reconfiguring their own IP addresses. Some older operating systems do not support DHCP. If you have such systems you may be able to upgrade them. If this is not possible they may support the older BOOTP protocol, and a DHCP server can be chosen that will support this option. For peace of mind, it is a good idea to decide what is important to you, which of the available DHCP servers is best suited to meet your specific requirements and always get a second opinion.<br /><br /><strong>How is it different than BOOTP or RARP?</strong><br />DHCP is based on BOOTP and maintains some backward compatibility. The main difference is that BOOTP was designed for manual pre-configuration of the host information in a server database, while DHCP allows for dynamic allocation of network addresses and configurations to newly attached hosts. Additionally, DHCP allows for recovery and reallocation of network addresses through a leasing mechanism. RARP is a protocol used by Sun and other vendors that allows a computer to find out its own IP number, which is one of the protocol parameters typically passed to the client system by DHCP or BOOTP. RARP doesn't support other parameters and using it, a server can only serve a single LAN. DHCP and BOOTP are designed so they can be routed.<br /><br /><strong>Why shouldn't clients assign IP numbers without the use of a server?</strong><br />It is theoretically possible for client-machines to find addresses to use by picking an address out of the blue and broadcasting a request of all the other client machines to see if they are using them. Apple talk is designed around this idea, and Apple's MacTCP can be configured to do this for IP. However, this method of IP address assignment has disadvantages. A computer that needs a permanently-assigned IP number might be turned off and lose its number to a machine coming up. This has problems both for finding services and for security. A network might be temporarily divided into two non-communicating networks while a network component is not functioning. During this time, two different client-machines might end up claiming the same IP number. When the network comes back, they start malfunctioning. If such dynamic assignment is to be confined to ranges of IP addresses, then the ranges are configured in each desktop machine rather than being centrally administered. This can lead both to hidden configuration errors and to difficulty in changing the range. Another problem with the use of such ranges is keeping it easy to move a computer from one subnet to another.<br /><br /><strong>Can DHCP support statically defined addresses?</strong><br />Yes. At least there is nothing in the protocol to preclude this and one expects it to be a feature of any DHCP server. This is really a server matter and the client should work either way. The RFC refers to this as manual allocation.<br /><br /><strong>Can a BOOTP client boot from a DHCP server?</strong><br />Only if the DHCP server is specifically written to also handle BOOTP queries.<br /><br /><strong>Can a DHCP client boot from a BOOTP server?</strong><br />Only if the DHCP client were specifically written to make use of the answer from a BOOTP server. It would presumably treat a BOOTP reply as an unending lease on the IP address. In particular, the TCP/IP stack included with Windows 95 does not have this capability.<br /><br /><strong>Is a DHCP server "supposed to" be able to support a BOOTP client?</strong><br />The RFC on such interoperability (1534) is clear: "In summary, a DHCP server: ... MAY support BOOTP clients," (section 2). The word "MAY" indicates such support, however useful, is left as an option.<br /><br /><strong>Can a DHCP server back up another DHCP server?</strong><br />You can have two or more servers handing out leases for different addresses. If each has a dynamic pool accessible to the same clients, then even if one server is down, one of those clients can lease an address from the other server. However, without communication between the two servers to share their information on current leases, when one server is down, any client with a lease from it will not be able to renew their lease with the other server. Such communication is the purpose of the "server to server protocol" (see next question). It is possible that some server vendors have addressed this issue with their own proprietary server-to-server communication.<br /><br /><strong>In a subnetted environment, how does the DHCP server discover what subnet a request has come from?</strong><br />DHCP client messages are sent to off-net servers by DHCP relay agents, which are often a part of an IP router. The DHCP relay agent records the subnet from which the message was received in the DHCP message header for use by the DHCP server.<br />Note: a DHCP relay agent is the same thing as a BOOTP relay agent, and technically speaking, the latter phrase is correct.<br /><br /><strong>If a physical LAN has more than one logical subnet, how can different groups of clients be allocated addresses on different subnets?</strong><br />One way to do this is to preconfigure each client with information about what group it belongs to. A DHCP feature designed for this is the user class option. To do this, the client software must allow the user class option to be preconfigured and the server software must support its use to control which pool a client's address is allocated from.<br /><br /><strong>Can DHCP support remote access?</strong><br />PPP has its own non-DHCP way in which communications servers can hand clients an IP address called IPCP (IP Control Protocol) but doesn't have the same flexibility as DHCP or BOOTP in handing out other parameters. Such a communications server may support the use of DHCP to acquire the IP addresses it gives out. This is sometimes called doing DHCP by proxy for the client. I know that Windows NT's remote access support does this. A feature of DHCP under development (DHCPinform) is a method by which a DHCP server can supply parameters to a client that already has an IP number. With this, a PPP client could get its IP number using IPCP, then get the rest of its parameters using this feature of DHCP. SLIP has no standard way in which a server can hand a client an IP address, but many communications servers support non-standard ways of doing this that can be utilized by scripts, etc. Thus, like communications servers supporting PPP, such communications servers could also support the use of DHCP to acquire the IP addressees to give out.<br />I am not currently aware of any way in which DHCP can support client-computers served solely by PPP or SLIP. Such a computer doesn't have the IEEE-style MAC address that DHCP requires to act as its key to determining which client-computer is which within the same subnet. Communications servers that acquire IP numbers for their clients via DHCP run into the same roadblock in that they have just one MAC address, but need to acquire more than one IP address. One way such a communications server can get around this problem is through the use of a set of unique pseudo-MAC addresses for the purposes of its communications with the DHCP server. Another way (used by Shiva) is to use a different "client ID type" for your hardware address. lient ID type 1 means you're using MAC addresses. However, client ID type 0 means an ASCII string.<br /><br /><strong>How can I relay DHCP if my router does not support it?</strong><br />A server on a net(subnet) can relay DHCP or BOOTP for that net. Microsoft has software to make Windows NT do this.<br /><br /><strong>Can you limit which MAC addresses are allowed to roam?</strong><br />Sites may choose to require central pre-configuration for all computers that will be able to acquire a dynamic address. A DHCP server could be designed to implement such a requirement, presumably as an option to the server administrator.<br /><br /><strong>What are the Gotcha's?</strong><br />A malicious user could make trouble by putting up an unofficial DHCP server. The immediate problem would be a server passing out numbers already belonging to some computer yielding the potential for two or more "innocent bystander" nodes ending up with the same IP number. Net result is problems using the nodes, possibly intermittent of one or the other is sometimes turned off. A lot of problems are possible if a renegade server manages to get a client to accept its lease offering, and feeds the client its own version of other booting parameters. One scenario is a client that loads its OS over the network via tftp being directed to a different file (possibly on a different server), thus allowing the perpetrator to take over the client. Given that boot parameters are often made to control many different things about the computers' operation and communication, many other scenarios are just as serious. Note that BOOTP has the same vulnerabilities.<br />The "broadcast flag" DHCP includes a way in which client implementations unable to receive a packet with a specific IP address can ask the server or relay agent to use the broadcast IP address in the replies (a "flag" set by the client in the requests). The definition of DHCP states that implementations "should" honor this flag, but it doesn't say they "must". Some Microsoft TCP/IP implementations used this flag, which meant in practical terms, relay agents and servers had to implement it. A number of BOOTP-relay-agent implementations ( e.g. in routers) handled DHCP just fine except for the need for this feature, thus they announced new versions stated to handle DHCP.<br />Some of the virtual LAN schemes, i.e., those that use the packet's IP number to decide which "virtual LAN" a client-computer is on for the purposes of TCP/IP, don't work when using DHCP to dynamically assign addresses. DHCP servers and relay agents use their knowledge of what LAN the client-station is on to select the subnet number for the client-station's new IP address whereas such switches use the subnet number sent by the client-station to decide which (virtual) LAN to put the station on. Routers are sometimes configured so that one LAN on one port has multiple network (or subnet) numbers. When the router is relaying requests from such a LAN to the DHCP server, it must pass along as IP number that is associated with one of the network (or subnet) numbers. The only way the DHCP server can allocate addresses on one of the LAN's other network (or subnet) numbers is if the DHCP server is<br />specifically written to have a feature to handle such cases, and it has a configuration describing the situation.<br />The knowledge that a particular IP number is associated with a particular node is often used for various functions. Examples are: for security purposes, for network management, and even for identifying resources. Furthermore, if the DNS's names are going to identify IP numbers, the numbers, the IP numbers have to be stable. Dynamic<br />configuration of the IP numbers undercuts such methods. For this reason, some sites try to keep the continued use of dynamically allocable IP numbers to a minimum. With two or more servers serving a LAN, clients that are moved around (e.g. mobile clients) can end up with redundant leases. Consider a home site with two DHCP servers, a remote site with DHCP services, and a mobile client. The client first connects to the home site and receives an address from one of the two serves. He/she then travels to the remote site (without releasing the lease at the home site) and attempts to use the acquired address. It is of course NAK'ed and the client receives an address appropriate for the remote site. The client then returns home and tries to use the address from the remote site. It is NAK'ed but now the client broadcasts a DHCP DISCOVER to get a address. The server that holds the previous lease will offer the address back to the client but there is no guarantee that the client will accept that address; consequently, it is possible for the client to acquire an address on the other server and therefore have two leases within the site. The problem can be solved by using only one server per subnet/site and can be mitigated by short lease lengths. But in a very mobile environment, it is possible for these transient servers to consume more than their fair share of addresses. If departments, offices, or individuals run DHCP servers with their own small address pools on LANs shared by other departments, offices, or individuals, they can find that their addresses are being used by anyone on the LAN that happens to set their IP configuration to use DHCP.Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com0tag:blogger.com,1999:blog-1417917570575260537.post-34984819812987102802007-05-29T16:10:00.000+05:302007-05-29T16:37:20.232+05:30The Windows Vista FirewallWe all have heard at one time or another, about the Windows XP firewall and how useless it is. However true or untrue these statements are, they can effect the confidence of future Windows products security systems. This paper is intent upon educating the public on the facts of the subject matter. So, let's get with it...<br /><br /><span style="font-weight: bold;">The Difference:-</span><br />No third party software can lay claim to the fact that the Windows Firewall starts its protection once the computer is turned on. Is that important you ask? Absolutely. If a capable malware program could turn itself on at the same time that the computer starts to boot, common sense would dictate the danger of this. Now, knowing the fact that the Vista firewall 'does' start at boot, we need to confidently know that it is going to protect from boot.<br /><br /><span style="font-weight: bold;">The Interface:-</span><br />Microsoft and the Windows team have done something a little different with the Vista firewall. They have separated the firewall in to two different interfaces. The default interface is the basic one. At first glance, it looks identical to the Windows XP SP2 firewall. This basic interface is ON by default and loads basic settings for normal user protection. In most cases, this basic setting should work fine. Then they added an Advanced interface for the more security savvy individuals. This Advanced interface gives a greater flexibility over the firewalls settings.<br /><br /><span style="font-weight: bold;">The Basic Configuration:-</span><br />As I mentioned earlier, the Vista firewall is turned on by default and will be set to a 'basic' configuration. In this configuration, the firewall works in tandem with the new Windows Service Hardening feature. If the firewall should detect a certain activity that is deemed a prohibited behavior according to the Windows Service Hardenings preset rules, the firewall will block this suspect activity.<br />To access the Vista Firewalls basic settings; Click the <span style="font-style: italic;">Windows button</span>>> <span style="font-style: italic;">Control Panel</span>>> <span style="font-style: italic;">Windows Firewall</span>. With the Windows Firewall window open, you will see three tabs at the top; General, Exceptions and Advanced. Let's quickly discuss each tab separately:<br /><br /><span style="font-weight: bold;">General tab:-</span><br />With this tab selected, you will see three possible settings; On (default), Block all programs and Off. The on and off selections are pretty self-explanatory, but the "Block all programs" option is very handy if you need to login to an unsecure public wi-fi network. With this option selected in this scenario, you will be completely protected.<br /><br /><span style="font-weight: bold;">Exceptions tab:-</span><br />With this tab selected, you can view all of the programs that Windows has on its default block list. If you would like to unblock a certain program, just simply click the checkbox next to the programs name. Also, at the bottom of this window you will notice that you can add or delete programs. A little further down the window, you will notice an entry titled: "Tell me when Windows Firewall blocks a program". This is enabled by default, but if you would prefer not to get popup notifications regarding blocked programs, simply de-select this option and click Apply.<br /><br /><span style="font-weight: bold;">Advanced tab:-</span><br />With this tab selected, you will see the available network connections on your system that can be protected by the Windows Firewall. When you see a checkmark next to the available network connection, you'll know that it is being protected. Unchecking, of course, removes the protection.<br />Also available under the Advanced tab is a "<span style="font-style: italic;">Security logging</span>" feature. When you click the "<span style="font-style: italic;">Settings</span>" button under the Security logging feature, you will be able to create and configure log files of either dropped packets or successful connections to your network and set maximum log sizes.<br />Another feature you'll notice is "ICMP" (<span style="font-style: italic;">Internet Control Message Protocol</span>):<br />Here you are given a certain flexibility over how your computer is to respond to ICMP requests. When you click the Settings button, you will notice that the entry titled: "Allow incoming echo request" is the only entry selected (allowed). All other requests are not allowed by default.<br />The last available option under the Advanced tab is the "Default settings" options. When you click the "Restore Defaults" button, you will remove any previous settings changes that have been made and return the Windows Firewall back to its Default configuration. If you should get in to a little trouble while configuring your Basic settings, this is a good option to be aware of.<br /><br /><span style="font-weight: bold;">The Advanced Configuration:-</span><br />This is where Microsoft has added a second completely separate interface for the Windows Firewall. In order to view and configure advanced settings, you will first need to create a custom MMC (Microsoft Management Console). The purpose for this is to dissuade any novice users from accessing these settings. If you would like to create a custom MMC, here's how:<br /><ol><li> Click the Windows button</li><li>In the Search box, enter: cmd</li><li>Right click the Run Program and select "Run as administrator" from the resulting menu.</li><li>In the Run window, type in: mmc.exe [Enter] or click OK.</li><li>With MMC open, go to File>> Add/Remove Snap-in.</li><li>Open the "Available Snap-ins" list and scroll the list to locate an entry titled: "Windows Firewall With Advanced Security".</li><li>Click to select the entry and then click the "Add" button.</li><li>Accept the default (Local Computer) from the Select Computer dialog box.</li><li>Click Finish, then OK. </li></ol>You will now be able to view the advanced settings in the MMC.<br /><br />From within the MMC, you have a great deal of flexibility over your Windows Firewall. Some interesting configurations worth noting are:<br /><br /><span style="font-weight: bold;">Multiple Firewall Profiles:-</span><br />More geared around portable computing, this available option allows you to configure three different profiles for different situations. As an example, if your are traveling and are using your laptop in a public unsecured wi-fi environment, you can enable your "Public" profile. Switch to your "Private" network configured profile when surfing at home, or rely upon your "Domain" configured profile for work. Each profile tab has the same available settings changes available.<br />Once you've clicked one of the profile tabs, you can turn the selected profile On or Off. You also have the flexibility over Inbound and Outbound connections. By default as we have learned earlier, outbound connections are allowed and Inbound connections are NOT allowed (selected 'exceptions' are allowed). In the MMC, you can change these settings to fit your personal needs.<br /><br /><span style="font-weight: bold;">IPSec Configuration:-</span><br />Another tab you'll see along side each of the three profiles is the IPSec tab. IPSec (Internet Protocol Security) is a constantly developing security standard that provides for security of sensitive data that is transmitted over unprotected networks. With the IPSec tab selected, you can click the "Custom" button to configure these settings to fit your needs. Available configuration options are: Key Exchange, Data Protection and Authorization Method.<br /><br /><span style="font-weight: bold;">Connection Security Rules:-</span><br />After you have setup all of your profiles and configured your IPSec settings, you're now ready to setup your connection security rules. You will be guided by a wizard that helps you create security rules to determine how and when secure connections are to be applied between an individual computer or even a group of computers. Some of the flexibilities you will have here are:<br /><ul><li> Isolate certain connections and restrict a connection based on a domains membership or health status.</li><li>Set up server-to-server authentication rules</li><li>Restrict certain connections</li><li>Exemplify certain computers from authentication</li><li>Create a custom rule when nothing available applies</li></ul>Once you've created your rules, you can easily delete them by right clicking and selecting Delete. Or, you can save them for a later time by selecting Disable instead. To enable the disabled rule, simply right click it and select Enable.Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com3tag:blogger.com,1999:blog-1417917570575260537.post-82114682196198407912007-05-08T17:34:00.000+05:302007-05-10T11:50:23.246+05:30Windows Media Player 10 Keyboard ShortcutsHide the menu : <span style="font-weight: bold;">ALT</span><br />Zoom to 50 percent : <span style="font-weight: bold;">ALT+1</span><br />Zoom to 100 percent : <span style="font-weight: bold;">ALT+2</span><br />Zoom to 200 percent : <span style="font-weight: bold;">ALT+3</span><br />Show or hide album information in the Rip feature : <span style="font-weight: bold;">ALT+A</span><br />Start burning a CD in the Burn feature : <span style="font-weight: bold;">ALT+B</span><br />Rip music from a CD to your computer in the Rip feature : <span style="font-weight: bold;">ALT+C</span><br />Show video in full screen : <span style="font-weight: bold;">ALT+ENTER</span><br />Show the File menu : <span style="font-weight: bold;">ALT+F</span><br />Quit the program in the current window : <span style="font-weight: bold;">ALT+F4</span><br />Show the anchor window menu : <span style="font-weight: bold;">ALT+F6</span>, <span style="font-weight: bold;">ALT</span><br />Show the Help menu : <span style="font-weight: bold;">ALT+H</span><br />Show or hide album information in your library : <span style="font-weight: bold;">ALT+I</span><br />Save a new or changed playlist to your library : <span style="font-weight: bold;">ALT+L</span>, <span style="font-weight: bold;">A</span><br />Show a list of items to burn to CD in the List pane in your library : <span style="font-weight: bold;">ALT+L, B</span><br />Select the columns to be shown in your library : <span style="font-weight: bold;">ALT+L, C</span><br />Show a playlist from your library in the List pane. : <span style="font-weight: bold;">ALT+L, E</span><br />Shuffle items in the List Pane in your library : <span style="font-weight: bold;">ALT+L, H</span><br />Create a playlist or auto playlist in the List pane in your library : <span style="font-weight: bold;">ALT+L, N</span><br />Show or hide the List pane in your library : <span style="font-weight: bold;">ALT+L, S</span><br />Edit items in the List pane by using the Edit Playlist dialog box in your library : <span style="font-weight: bold;">ALT+L, U</span><br />Activate double-clicking to add selected items to the List pane in your library : <span style="font-weight: bold;">ALT+O, A</span><br />Show a list of items to burn to CD in the List pane in your library : <span style="font-weight: bold;">ALT+O, B</span><br />Select the columns to be shown in your library : <span style="font-weight: bold;">ALT+O, C</span><br />Select items in the Details pane of your library that contain media information for the selected sort order : <span style="font-weight: bold;">ALT+O, G</span><br />Activate double-clicking to play only selected items in a playlist in your library. : <span style="font-weight: bold;">ALT+O, I</span><br />Activate double-clicking to play all items in a playlist in your library : <span style="font-weight: bold;">ALT+O, P</span><br />Play items in the Now Playing list repeatedly in your library : <span style="font-weight: bold;">ALT+O, R</span><br />Show or hide the List pane in your library : <span style="font-weight: bold;">ALT+O, S</span><br />Show a list of items to play in the List pane in your library : <span style="font-weight: bold;">ALT+O, W</span><br />Show the Play menu : <span style="font-weight: bold;">ALT+P</span><br />Search for items in your library that include the text in the Search box : <span style="font-weight: bold;">ALT+S</span><br />Restore the Player from mini Player mode : <span style="font-weight: bold;">ALT+SHIFT+P</span><br />Show the Tools menu : <span style="font-weight: bold;">ALT+T</span><br />Show the View menu : <span style="font-weight: bold;">ALT+V</span><br />Go to the Features taskbar features : <span style="font-weight: bold;">ALT+V, G </span><br />Move left or right or up or down on menus or lists : <span style="font-weight: bold;">Arrow keys</span><br />Switch to full mode : <span style="font-weight: bold;">CTRL+1</span><br />Switch to skin mode : <span style="font-weight: bold;">CTRL+2</span><br />Select or clear check boxes for multiple items that are not contiguous : <span style="font-weight: bold;">CTRL+arrow keys, SPACEBAR</span><br />Play the previous item : <span style="font-weight: bold;">CTRL+B </span><br />Edit the current playlist on the File menu : <span style="font-weight: bold;">CTRL+D</span><br />Eject the CD or DVD on the Play menu : <span style="font-weight: bold;">CTRL+E</span><br />Play the next item : <span style="font-weight: bold;">CTRL+F</span><br />Shuffle the playlist on the Play menu or the Skin shortcut menu : <span style="font-weight: bold;">CTRL+H</span><br />Capture a still image from a DVD on the View menu : <span style="font-weight: bold;">CTRL+I</span><br />Show the menu bar in full mode : <span style="font-weight: bold;">CTRL+M</span><br />Create a playlist on the File menu : <span style="font-weight: bold;">CTRL+N</span><br />Open a file on the Skin shortcut menu or the File menu : <span style="font-weight: bold;">CTRL+O</span><br />Play or pause a file : <span style="font-weight: bold;">CTRL+P</span><br />Stop playback : <span style="font-weight: bold;">CTRL+S</span><br />Rewind (not available for all files) : <span style="font-weight: bold;">CTRL+SHIFT+B</span><br />Turn captions and subtitles on or off : <span style="font-weight: bold;">CTRL+SHIFT+C</span><br />Play faster than normal speed (time compression) : <span style="font-weight: bold;">CTRL+SHIFT+G</span><br />Play slower than normal speed (time expansion) : <span style="font-weight: bold;">CTRL+SHIFT+S</span><br />Repeat the playlist : <span style="font-weight: bold;">CTRL+T</span><br />Switch between the inner and outer areas of the Player : <span style="font-weight: bold;">CTRL+TAB</span><br />Specify either a URL or path of a file : <span style="font-weight: bold;">CTRL+U</span><br />Close or stop playing a file on the File menu : <span style="font-weight: bold;">CTRL+W</span><br />Delete a selected item in the Sync feature : <span style="font-weight: bold;">DELETE</span><br />Select the next item in the list : <span style="font-weight: bold;">DOWN ARROW</span><br />Play an item : <span style="font-weight: bold;">ENTER</span><br />Hide the menu : <span style="font-weight: bold;">ESC</span><br />Open Help : <span style="font-weight: bold;">F1</span><br />Search specified locations for digital media files : <span style="font-weight: bold;">F3</span><br />Refresh the information in the panes in the Sync feature : <span style="font-weight: bold;">F5</span><br />Mute the volume : <span style="font-weight: bold;">F8</span><br />Decrease the volume : <span style="font-weight: bold;">F9</span><br />Select or clear contiguous check boxes : <span style="font-weight: bold;">SHIFT+arrow keys, SPACEBAR</span><br />Show the shortcut menu for the selected item : <span style="font-weight: bold;">SHIFT+F10</span><br />Select the previous area : <span style="font-weight: bold;">SHIFT+TAB</span><br />Select or clear a check box : <span style="font-weight: bold;">SPACEBAR</span><br />Select the next area : <span style="font-weight: bold;">TAB</span><br />Select the previous item in the list : <span style="font-weight: bold;">UP ARROW<br /></span>Thanks for <a href="http://www.microsoft.com/windows/windowsmedia/knowledgecenter/">Windows Media.</a><span style="text-decoration: underline;"></span>Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com106tag:blogger.com,1999:blog-1417917570575260537.post-19129008803584849752007-05-08T10:25:00.000+05:302007-05-08T11:46:57.289+05:30FAT32 ( File Allocation Table 32 )<span style="FONT-WEIGHT: bold">What is this FAT32 I keep hearing about?</span><br />FAT32 is a new feature introduced by Microsoft to reduce wasted cluster space. You can find FAT 32 in the OSR2 version of Windows 95.<br /><br /><span style="FONT-WEIGHT: bold">What is the difference between FAT16 & FAT32?</span><br />Inside every hard drive, there are clusters. The larger the partition, the bigger the cluster size. Many people resort to partition their hard drive into smaller partitions to reclaim wasted cluster disk space. FAT32 reduces the cluster size so you don't have to partition your hard drive to save disk space. The table below shows the difference:<span style="COLOR: rgb(0,0,255)"><b><br />FAT16</b></span><br /><table border="1"><tbody><tr><td style="TEXT-ALIGN: center"><p align="left"><b>Cluster size</b></p></td><td style="TEXT-ALIGN: center"><p align="left"><b>Partition Size</b></p></td></tr><tr><td align="middle"><p align="left">2 KB</p></td><td align="middle"><p align="left">128 MB</p></td></tr><tr><td align="middle"><p align="left">4 KB</p></td><td align="middle"><p align="left">256 MB</p></td></tr><tr><td align="middle"><p align="left">8 KB</p></td><td align="middle"><p align="left">512 MB</p></td></tr><tr><td align="middle"><p align="left">16 KB</p></td><td align="middle"><p align="left">1 GB</p></td></tr><tr><td align="middle"><p align="left">32 KB</p></td><td align="middle"><p align="left">2 GB</p></td></tr></tbody></table><br /><div align="left"><span style="COLOR: rgb(0,0,255)"><b>FAT32<br /></div></b></span><table border="1"><tbody><tr><td><p align="left"><b>Cluster size</b></p></td><td align="middle"><p align="left"><b>Partition Size</b></p></td></tr><tr><td align="middle"><p align="left">2 KB</p></td><td align="middle"><p align="left"><></p></td></tr><tr><td align="middle"><p align="left">4 KB</p></td><td align="middle"><p align="left">260 MB - 8 GB</p></td></tr><tr><td align="middle"><p align="left">8 KB</p></td><td align="middle"><p align="left">8 GB - 16 GB</p></td></tr><tr><td align="middle"><p align="left">16 KB</p></td><td align="middle"><p align="left">16 GB - 32 GB</p></td></tr><tr><td align="middle"><p align="left">32 KB</p></td><td align="middle"><p align="left">32 GB<</p></td></tr></tbody></table><br /><span nd="3">As you can see, the maximum partition size under FAT16 is only 2 GB while FAT32 supports up to 32GB. And also, the cluster size for a 2GB partition is 32 KB while a partition between 260 MB to 16 GB ( for home or personal use range ) 's cluster size is 4 KB, saving nearly 8 times less cluster space than a partition that is under FAT16.<br /></span><br /><span style="FONT-WEIGHT: bold">Does that means that I will have FAT32 installed if I have OSR2?</span><br /><br /><div style="TEXT-ALIGN: left">Yes and no. It depends on how your OSR2 was installed. If installed from the setup disk ( included in your package ) then setup will format your hard drive leaving you with a FAT32 hard drive. But if OSR2 is installed from DOS or the earlier version of Windows 95, then you will be using the old FAT16.<br /></div><br /><span style="FONT-WEIGHT: bold">I have a copy of OSR2. What is the most common way to convert my hard drive to support FAT32?</span><br />The most common way is to format the whole hard drive. Boot to command prompt and run setup from the OSR2 CD. Go along setup until you are prompted to make a boot disk. Insert an empty disk and label it OSR2 boot disk. Then, cancel setup. Now boot your PC from the boot disk. Format the hard drive from the boot disk using the format command. (Note: Do not use the /q switch as it will just erase all data. Use full format.) After your hard drive is formatted, it will support FAT32.<br /><br /><span style="FONT-WEIGHT: bold">Is there any other way I can convert FAT16 to FAT32 without formatting my hard drive?</span><br />Yes, by using some third party software or utilities.<br /><br /><span style="FONT-WEIGHT: bold">What are the utilities that can convert FAT16 to FAT32?</span><br />Microsoft has released one that is currently available at the Microsoft site. Powerquest also have developed one as part of Partition Magic. We believe there are also other FAT32 conversion utilities on the Internet written by shareware of freeware authors. Also, Windows 98 ships with a FAT32 converter.<br /><br /><span style="FONT-WEIGHT: bold">Can I install OSR2 on a FAT16 partition/drive?</span><br />OSR2 does not need FAT32 to be installed. OSR2 will run happily on any FAT16 partition / drive.Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com2tag:blogger.com,1999:blog-1417917570575260537.post-29372914603654740942007-05-07T11:06:00.000+05:302007-05-07T10:57:40.066+05:30Windows Registry FAQ<strong>What is the Registry?</strong><br />The Registry is a database used to store settings and options for the 32 bit versions of Microsoft Windows including Windows 95, 98, ME and NT/2000. It contains information and settings for all the hardware, software, users, and preferences of the PC. Whenever a user makes changes to a Control Panel settings, or File Associations, System Policies, or installed software, the changes are reflected and stored in the Registry.<br />The physical files that make up the registry are stored differently depending on your version of Windows; under Windows 95, 98 & ME it is contained in two hidden files in your Windows directory, called <strong>USER.DAT </strong>and <strong>SYSTEM.DAT</strong>, while under Windows NT/2000 the files are contained separately in the %SystemRoot%\System32\Config directory. You can not edit these files directly, you must use a tool usually known as a "Registry Editor" to make any changes (using registry editors will be discussed later in the article).<br /><br /><strong>The Structure of the Registry</strong><br />The Registry has a hierarchal structure, although it looks complicated the structure is similar to the directory structure on your hard disk, with Regedit being similar to Windows Explorer.<br /><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiCJA8gc-qF2UcfU8TmPYpJcHbHNbBBjn1Z-cu3BcPt42JfQd5BiwOW1hZs4An9dfO9eL0PwdENCoHeWupQuT4ySXjWxlFvfSp06xQhbzoVNtgbjFIS0Ep0qJ-3afqLlpOK9GXsygoYH8te/s1600-h/registry_tree.gif"><img id="BLOGGER_PHOTO_ID_5061332371895341842" style="margin: 0px 10px 10px 0px; float: left;" alt="" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiCJA8gc-qF2UcfU8TmPYpJcHbHNbBBjn1Z-cu3BcPt42JfQd5BiwOW1hZs4An9dfO9eL0PwdENCoHeWupQuT4ySXjWxlFvfSp06xQhbzoVNtgbjFIS0Ep0qJ-3afqLlpOK9GXsygoYH8te/s200/registry_tree.gif" border="0" /></a><br />Each main branch (denoted by a folder icon in the Registry Editor, see left) is called a <strong>Hive</strong>, and Hives contains<strong> Keys</strong>. Each key can contain other keys (sometimes referred to as sub-keys), as well as <strong>Values</strong>. The values contain the actual information stored in the Registry. There are three types of values; String, Binary, and DWORD - the use of these depends upon the context.<br /><br /><br />There are six main branches, each containing a specific portion of the information stored in the Registry. They are as follows:<br /><ul><li><strong>HKEY_CLASSES_ROOT</strong> - This branch contains all of your file association types, OLE information and shortcut data. </li><li><strong>HKEY_CURRENT_USER</strong> - This branch links to the section of HKEY_USERS appropriate for the user currently logged onto the PC.</li><li><strong>HKEY_LOCAL_MACHINE</strong> - This branch contains computer specific information about the type of hardware, software, and other preferences on a given PC, this information is used for all users who log onto this computer.</li><li><strong>HKEY_USERS</strong> - This branch contains individual preferences for each user of the computer, each user is represented by a SID sub-key located under the main branch.</li><li><strong>HKEY_CURRENT_CONFIG</strong> - This branch links to the section of HKEY_LOCAL_MACHINE appropriate for the current hardware configuration.</li><li><strong>HKEY_DYN_DATA</strong> - This branch points to the part of HKEY_LOCAL_MACHINE, for use with the Plug-&-Play features of Windows, this section is dymanic and will change as devices are added and removed from the system. </li></ul><p>Each registry value is stored as one of five different data types:</p><ul><li><strong>REG_BINARY</strong> - This type stores the value as raw binary data. Most hardware component information is stored as binary data, and can be displayed in an editor in hexadecimal format.</li><li><strong>REG_DWORD</strong> - This type represents the data by a four byte number and is commonly used for boolean values, such as "0" is disabled and "1" is enabled. Additionally many parameters for device driver and services are this type, and can be displayed in REGEDT32 in binary, hexadecimal and decimal format, or in REGEDIT in hexadecimal and decimal format.</li><li><strong>REG_EXPAND_SZ</strong> - This type is an expandable data string that is string containing a variable to be replaced when called by an application. For example, for the following value, the string "%SystemRoot%" will replaced by the actual location of the directory containing the Windows NT system files. (This type is only available using an advanced registry editor such as REGEDT32)</li><li><strong>REG_MULTI_SZ</strong> - This type is a multiple string used to represent values that contain lists or multiple values, each entry is separated by a NULL character. (This type is only available using an advanced registry editor such as REGEDT32)</li><li><strong>REG_SZ</strong> - This type is a standard string, used to represent human readable text values. </li></ul><strong>Editing the Registry</strong><br />The Registry Editor (REGEDIT.EXE) is included with most version of Windows (although you won't find it on the Start Menu) it enables you to view, search and edit the data within of the Registry. There are several methods for starting the Registry Editor, the simplest is to click on the <strong>Start</strong> button, then select <strong>Run</strong>, and in the <strong>Open </strong>box type "regedit", and if the Registry Editor is installed it should now open and look like the image below.<br /><a href="http://www.flickr.com/photo_zoom.gne?id=487740480&size=o"><img id="BLOGGER_PHOTO_ID_5061336366214927138" style="margin: 0px auto 10px; display: block; text-align: center;" alt="" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjlqGCYmH9v15g5apxCYIjWKl0e9t8KaXLVQ9DekM6x6Pkm21e1WAzxS9mbA3mm_kiEXEVy2hfRpvzjypRL_QkH6dy3Cp-h1a39UFZpQ41_6Sbe-fjdPVcrj0qkU-zSrRDPLskaJxo-doQD/s200/re.PNG" border="0" /></a>An alternative Registry Editor (REGEDT32.EXE) is available for use with Windows NT/2000, it includes some additional features not found in the standard version, including; the ability to view and modify security permissions, and being able to create and modify the extended string values REG_EXPAND_SZ & REG_MULTI_SZ. <strong>Create a Shortcut to Regedit<br /></strong>This can be done by simply right-clicking on a blank area of your desktop, selecting New, then Shortcut, then in the Command line box enter "regedit.exe" and click Next, enter a friendly name (e.g. 'Registry Editor') then click Finish and now you can double click on the new icon to launch the Registry Editor.<br /><br /><p><strong>Using Regedit to modify your Registry </strong><br />Once you have started the Regedit you will notice that on the left side there is a tree with folders, and on the right the contents (values) of the currently selected folder. </p><p>Like Windows explorer, to expand a certain branch (see the structure of the registry section), click on the plus sign [+] to the left of any folder, or just double-click on the folder. To display the contents of a key (folder), just click the desired key, and look at the values listed on the right side. You can add a new key or value by selecting New from the Edit menu, or by right-clicking your mouse. And you can rename any value and almost any key with the same method used to rename files; right-click on an object and click rename, or click on it twice (slowly), or just press F2 on the keyboard. Lastly, you can delete a key or value by clicking on it, and pressing Delete on the keyboard, or by right-clicking on it, and choosing Delete. </p><p><em>Note: it is always a good idea to backup your registry before making any changes to it. It can be intimidating to a new user, and there is always the possibility of changing or deleting a critical setting causing you to have to reinstall the whole operating system. It's much better to be safe than sorry!<br /></em><br /><strong>Importing and Exporting Registry Settings<br /></strong>A great feature of the Registry Editor is it's ability to import and export registry settings to a text file, this text file, identified by the .REG extension, can then be saved or shared with other people to easily modify local registry settings. You can see the layout of these text files by simply exporting a key to a file and opening it in Notepad, to do this using the Registry Editor select a key, then from the "Registry" menu choose "Export Registry File...", choose a filename and save. If you open this file in notepad you will see a file similar to the example below:<br /><br />REGEDIT4<br />[HKEY_LOCAL_MACHINE\SYSTEM\Setup]<br />"SetupType"=dword:00000000<br />"CmdLine"="setup -newsetup"<br />"SystemPrefix"=hex:c5,0b,00,00,00,40,36,02 </p><p>The layout is quite simple, <strong>REGEDIT4</strong> indicated the file type and version, <strong>[HKEY_LOCAL_MACHINE\SYSTEM\Setup]</strong> indicated the key the values are from, <strong>"SetupType"=dword:00000000</strong> are the values themselves the portion after the "=" will vary depending on the type of value they are; DWORD, String or Binary.</p><p>So by simply editing this file to make the changes you want, it can then be easily distributed and all that need to be done is to double-click, or choose "Import" from the Registry menu, for the settings to be added to the system Registry. </p><p><strong>Deleting keys or values using a REG file </strong><br />It is also possible to delete keys and values using REG files. To delete a key start by using the same format as the the REG file above, but place a "-" symbol in front of the key name you want to delete. For example to delete the [HKEY_LOCAL_MACHINE\SYSTEM\Setup] key the reg file would look like this:<br />REGEDIT4<br />[-HKEY_LOCAL_MACHINE\SYSTEM\Setup]</p><p>The format used to delete individual values is similar, but instead of a minus sign in front of the whole key, place it after the equal sign of the value. For example, to delete the value "SetupType" the file would look like:<br /><br />REGEDIT4<br />[HKEY_LOCAL_MACHINE\SYSTEM\Setup]<br />"SetupType"=- </p><p>Use this feature with care, as deleting the wrong key or value could cause major problems within the registry, so remember to always make a backup first</p><p><strong>Regedit Command Line Options </strong><br />Regedit has a number of command line options to help automate it's use in either batch files or from the command prompt. Listed below are some of the options, please note the some of the functions are operating system specific</p><p>regedit.exe [options] [filename]<br /><br />filename Import .reg file into the registry<br />/s Silent, i.e. hide confirmation box when importing files<br />/e Export registry file<br />e.g. regedit /e file.reg HKEY_USERS\.DEFAULT<br />/L:system Specify the location of the system.dat to use<br />/R:user Specify the location of the user.dat to use<br />/C Compress [filename] (Windows 98</p><p><strong>Maintaining the Registry </strong><br /><strong>How can you backup and restore the Registry</strong></p><p><strong>Windows 95 </strong><br />Microsoft included a utility on the Windows 95 CD-ROM that lets you create backups of the Registry on your computer. The Microsoft Configuration Backup program, CFGBACK.EXE, can be found in the \Other\Misc\Cfgback directory on the Windows 95 CD-ROM. This utility lets you create up to nine different backup copies of the Registry, which it stores, with the extension RBK, in your \Windows directory. If your system is set up for multiple users, CFGBACK.EXE won't back up the USER.DAT file.<br />After you have backed up your Registry, you can copy the RBK file onto a floppy disk for safekeeping. However, to restore from a backup, the RBK file must reside in the \Windows directory. Windows 95 stores the backups in compressed form, which you can then restore only by using the CFGBACK.EXE utility</p><p><strong>Windows 98 </strong><br />Microsoft Windows 98 automatically creates a backup copy of the registry every time Windows starts, in addition to this you can manually create a backup using the Registry Checker utility by running SCANREGW.EXE from Start Run menu</p><p><strong>What to do if you get a Corrupted Registry<br /></strong>Windows 95, 98 and NT all have a simple registry backup mechanism that is quite reliable, although you should never simply rely on it, remember to always make a backup first</p><p><strong>Windows 95 </strong><br />In the Windows directory there are several hidden files, four of these will be <strong>SYSTEM.DAT & USER.DAT</strong>, your current registry, and <strong>SYSTEM.DAO & USER.DAO</strong>, a backup of your registry. Windows 9x has a nice reature in that every time it appears to start successfully it will copy the registry over these backup files, so just in case something goes wrong can can restore it to a known good state. To restore the registry follow these instruction: </p><p>1.Click the Start button, and then click Shut Down </p><p>2.Click Restart The Computer In MS-DOS Mode, then click Yes. </p><p>3.Change to your Windows directory. For example, if your Windows directory is c:\windows, you would type the following: </p><p><em>cd c:\windows</em></p><p>4.Type the following commands, pressing ENTER after each one. (Note that SYSTEM.DA0 and USER.DA0 contain the number zero.) </p><p><em>attrib -h -r -s system.dat<br />attrib -h -r -s system.da0<br />copy system.da0 system.dat<br />attrib -h -r -s user.dat<br />attrib -h -r -s user.da0<br />copy user.da0 user.dat</em></p><p>5.Restart your computer </p><p>Following this procedure will restore your registry to its state when you last successfully started your computer.</p><p><strong>If all else fails</strong>, there is a file on your hard disk named SYSTEM.1ST that was created when Windows 95 was first successfully installed. If necessary you could also change the file attributes of this file from read-only and hidden to archive to copy the file to C:\WINDOWS\SYSTEM.DAT. </p><p><strong>Windows NT </strong><br />On Windows NT you can use either the "Last Known Good" option or RDISK to restore to registry to a stable working configuration. </p><p><strong>How can I clean out old data from the Registry? </strong><br />Although it's possible to manually go through the Registry and delete unwanted entries, Microsoft provides a tool to automate the process, the program is called RegClean. RegClean analyzes Windows Registry keys stored in a common location in the Windows Registry. It finds keys that contain erroneous values, it removes them from the Windows Registry after having recording those entries in the Undo.Reg file. You can download this free utility from our <a href="http://freepctech.com/">downloads page</a>.</p>Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com0tag:blogger.com,1999:blog-1417917570575260537.post-80533891429359508642007-05-06T19:48:00.000+05:302007-05-06T09:56:51.473+05:30Linux Online FAQ<span style="font-weight: bold;">What is Linux?</span><br />Linux is a Unix-like operating system originally developed by Linus Torvalds in 1991. To get the whole story, see our Page devoted entirely to this question.<br /><br /><span style="font-weight: bold;">Where can I get Linux?</span><br />here are literally hundreds of places you can get Linux because there are hundreds of "versions" or distributions of Linux. If you think you might want Linux because you're considering alternatives to Microsoft Windows or Macintosh OS for everyday computer use, you may want to check out a version of Linux called 'Knoppix', which will boot from your CD drive and does not need to be installed. If you're interested in Linux for other reasons, we invite you to look at our list of Linux distributions. You'll likely find what you're looking for there.<br /><br /><span style="font-weight: bold;">What is a Linux distribution?</span><br />A Linux "distribution" is version of the Linux operating system made especially by a company, organization or individual. The one thing they all have in common is that they use the Linux kernel. From there on, each developer will add its own programs, tools and other applications. Some are dedicated to specific uses while others are intended for the general public. Again, you'll find more information at our Linux distributions page.<br /><br /><span style="font-weight: bold;">Which Linux distribution do you recommend?</span><br />Linux Online tries to be impartial, particularly when it comes to for-profit, commercial distributions. We really don't recommend any one distribution over others. Also, there are so many factors to take into account when choosing a distribution that it would be impossible to make recommendations in general.<br /><br /><span>Can we have permission to use the Linux penguin logo?</span><br />Larry Ewing is the creator of the Linux penguin, Tux. Larry was kind enough to give free license to use it when he created it provided you give the correct attributions. If you're in doubt, please have a look at his website for more information. http://www.isc.tamu.edu/~lewing/linux/<br /><br /><span>Can you please forward this email/letter/gift/etc to Linus Torvalds?</span><br />Linus Torvalds does not work here at Linux Online so we don't handle any of Linus' correspondence. At present, he is working full-time on the kernel for the Open Source Development Labs. Please contact them if you need to get in touch with Linus or you wish to send him something. http://www.osdl.org/about_osdl/contact_osdl.html<br /><br /><span>Can you please send me Linux CDs?</span><span style="font-style: italic;"><br /></span> Linux Online is a general information site about Linux. It is not a retailer of CDs, therefore we can't send you commercial versions of Linux. As far as non-commercial versions go, we do not have the staff and means to handle the enormous amount of potential requests for CDs. We do provide a list of retailers who can send you CDs of Linux distributions - some at very low cost.<br /><br /><span style="font-weight: bold;">Where can I find a driver for my hardware?</span><br />As Linux grows in popularity, it also gains support for a wider range of hardware. The Linux kernel now supports and enormous amount of hardware and most major Linux distribution incorporate this support into their products. You can also get hardware support by downloading, compiling and installing the latest version of the Linux kernel. In some cases, hardware manufacturers want to provide Linux support without incorporating their drivers into the kernel, so they provide separate drivers. If you're looking for these it's best to consult the manufacturer's website or send them an inquiry by email. Then there are some hardware manufacturers who don't support Linux, so no drivers are available. If you're already running Linux, it's best to check to see if new hardware you want to purchase is supported.<br /><br /><span>Can I run applications for MS Windows on Linux?</span><br />The short answer to this is: no, not automatically and not directly. That is to say, Microsoft Windows and Linux applications cannot run the same applications because they are not designed in the same way. However, there are some ways to run programs for Microsoft Windows on Linux using emulators and other means. If you need/want to run an application designed for Microsoft Windows on Linux, you might want to check out the following applications:<br /><ul><li>WINE<br /></li><li>Crossover Products<br /></li><li>Win4Lin<br /></li><li>VMWare</li></ul><span style="font-weight: bold;">What does GNU/Linux refer to?</span><br />NU/Linux is the name Richard Stallman, founder of the Free Software Foundation and the GNU project, and its supporters prefer over just Linux. They cite the fact that Linux could not have come into being without tools from the GNU project. Though this is true, use and custom has favored just Linux over GNU/Linux in the public consciousness. This website's use of the term Linux in no way tries to minimize the contributions of the Free Software Foundation. We feel that it's easier for people to identify the operating system by that simpler name and in the end, that helps in its adoption.<br /><br /><span style="font-weight: bold;">Is Linux a company?</span><br />There is no company called Linux. Linux is an operating system. There are many companies that develop Linux products and provide services based on Linux, but not one called Linux who "controls" the operating system.<br /><br /><span style="font-weight: bold;">Can I buy stock in Linux?</span><br />As we mentioned in the previous answer, there is no company called "Linux", so there can't be any stock in a non-existent company. However, several companies are publicly traded who do provide Linux products and services. Here are a few that directly produce the Linux operating system.<br /><ul><li>Novell (Symbol: NOVL)</li><li>Red Hat (Symbol: RHAT)</li></ul>Companies like IBM and Hewlett-Packard have also put tremendous support behind Linux and they are publicly traded.<br /><br /><span style="font-weight: bold;">Who is SCO?</span><br />SCO or officially The SCO Group is the latest incarnation of what was founded as Caldera, formerly a Linux distribution company. In 2000, Caldera bought the Unix division of a company known as the Santa Cruz Operation (or SCO) and apparently acquired some rights to distribute the Unix operating system. New management took over at Caldera in 2002 and in early 2003, members of this new management team decided to abandon development of their Linux distribution and in a remarkable about-face, filed suit against IBM alleging that the computing giant had put Unix technology, which it claims it controls, into the Linux kernel in violation of contractual obligations. Caldera shortly after the suit was filed, officially changed their name to The SCO Group and is popularly known as SCO. This has since blown up into a huge controversy. For more information, see our page dedicated to the SCO case.<br /><br /><span style="font-weight: bold;">Does SCO own Linux?</span><br />They would like you to believe that they do. They will even sell you a Linux license under the threat that if you don't, they could sue you. However, we believe this is a lot like a paternity suit, just a bit more complicated.Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com1tag:blogger.com,1999:blog-1417917570575260537.post-71323347702244244262007-04-09T16:50:00.000+05:302007-04-09T17:23:19.594+05:30How Does Secure Socket Layer (SSL) Work?The Secure Socket Layer, SSL for short, is a protocol by which many services that communicate over the Internet can do so in a secure fashion. Before we discuss how SSL works and what kinds of security it provides, let us first see what happens without SSL.<br /><br /><span style="font-weight: bold;">Life on the Internet without SSL</span><br />Let us make an analogy between communications between computers on the Internet and communications between people over the telephone. Without SSL, your computer-to-computer communications suffer from the same security problems from which your telephone communications suffer:<br /><ul><li><b>Who are you talking to?</b>In a phone conversation, how can you be sure that the person who picks up the phone at the other end is really the person you are trying to call (especially if you have never spoken to them before)? What if your phone call was intercepted or re-routed, or what if someone else is answering your call recipient's phone? There really is no way to be sure you have reached the right person, especially if they are trying to fool you.</li><li><b>Eavesdropping?</b> As you are aware of from watching TV or reading, it is very easy to tap phone lines: the police and spies do this all the time to covertly gather information. It is not easy to detect if your lines are tapped. The same applies with communications over the Internet - how can you be sure that your communications are not being "tapped" and recorded?</li></ul>This results in two very real security issues for communications over the Internet: 1. knowing for sure that you are connecting to the right computers (i.e. those at your bank and not those at a hacker's or phisher's web site), and 2. knowing that your data is safe from prying eyes during transit to those computers. This is where SSL comes in.<br /><br /><span style="font-weight: bold;">Enter the Secure Socket Layer (SSL)</span><br />To solve these problems to a large degree, most Internet services support use of SSL as a mechanism for securing communications. To illustrate how SSL works, let us use another analogy.<br />Client wants to communicate with Company to send important information back and forth. Client wants to be 100% sure that s/he is communicating with Company and that no one can eavesdrop on the communications. How can s/he do this?<br /><ul><li>Client sends a courier to the Company's address.</li><li>The company has envelopes that, when closed, can only be opened by the company. The company and the courier go together to a trusted third party - a notary - which makes the company provide documentation to prove its identity. The notary certifies the company's secure envelopes and the courier takes these back to the client.</li><li>The client gets the envelopes and, if it trusts the notary's reputation, can be sure that they are actually from the company indicated.</li><li>The client also has secure envelopes that, once sealed, only the client can open. It puts some of these in one of the company's secure envelopes and sends them back to the company.</li><li>The company gets the sealed secure envelope. It opens the envelope (as only it can). It now has the client's secure envelopes.</li><li>The company has another kind of envelope that can be opened and sealed only by using a special combination. The company puts this special envelope with the combination lock, together with the combination, into one of the client's secure envelopes. The company seals the envelope.</li><li>The company has another type of secure envelope that anyone can open, but which only the company can seal. If you open one of these sealed envelopes, you know for sure that it was sent by the company. The company puts the whole package inside this and sends it to the client.</li><li>When the client gets the secure envelope, it opens it and thus knows that it came from the company. It then opens the next secure envelope inside that can only be opened by the client. Inside it gets out the combination-envelope and the combination itself.</li><li>The client the puts his data in the combination envelope, seals it and sends it to the company.</li><li>The company receives it, opens it, and puts the response in the same secure envelope and sends it back. </li><li>The procedure is repeated as often as necessary for required communications.</li></ul>SSL relies on the concept of "public key cryptography" to accomplish these tasks. In normal encryption, the two parties communicating share a "password" and that password is used to both encrypt and decrypt messages. While this is fast and efficient, how do you communicate passwords to people you have not yet met in a way that is itself secure?<br />In "public key cryptography", each person has two keys - a "public" key and a "private" key. Anything encrypted with the user's public key can only be decrypted with the private key and vice versa. Each person then tells the world what his public key is and keeps his private key safe and secure, and private.<br />If John sends Mary a message encrypted with Mary's public key, then only Mary can open it, as only she has her private key. This is like an envelope that anyone can seal but which only Mary can open.<br />If John sends Mary a message encrypted with John's private key, then anyone can open it, as everyone has access to John's public key. However, successfully opening the message proves that it was sent by John and no one else, as only John has access to his private key. This is like an envelope that only John can seal, but which anyone can open and thus prove that John sealed it.<br /><br /><span style="font-weight: bold;">SSL in Action</span><br />So, lets see how SSL actually works for securing your communications over the Internet. Before the communications occur, the following takes place:<br /><ul><li> Company wishes to secure communications to their server <tt>company.com</tt>.</li><li> They create a public and private key for <tt>company.com</tt> (this is also known as a "certificate").</li><li> They go to a "Trusted" third party company such as Thawte or Verisign: Thawte makes Company prove its identity and right to use the <tt>company.com</tt> domain. This usually involves a lot of paperwork and paying a hefty fee.</li><li> Once the verification is complete, Thawte gives Company a new public key that has some additional information in it. This information is the certification from Thawte that this public key is for Company and <tt>company.com</tt> and that this is verified by Thawte. This certification information is encrypted using Thawte's private key... we will see why below.</li></ul>Then, when Client wishes to communicate with Company at <tt>company.com</tt>,<br /><ul><li>Client makes a connection to <tt>company.com</tt> with its computer. This connection is made to a special "port" (address) on <tt>company.com</tt> that is set up for SSL communications only.</li><li>When Client connects to <tt>company.com</tt> on its SSL-secured port, Company sends back its public key.</li><li>Client gets the public key and decides if it is OK...</li></ul> 1. If the public key has expired, this could be a problem<br /> 2. If the public key claims to be for some domain that is not <tt>company.com</tt> that could be a problem.<br /> 3.Client has the public key for Thawte (and many other third party companies) stored in its computer - because these come with the computer. Thus, client can decrypt the validation information, prove the validation is from Thawte and verify that the public key is certified by Thawte. If Client trusts Thawte, then Client can trust that he/she is really communicating with Company. If Client doesn't trust Thawte, or whatever Third Party company is actually being used, then the identity of who is running the computers to which Client is connecting is suspect.<br /><ul><li>If client decides to trust the public key, then Client will send to Company the Client's public key.</li><li>Company will then generate a "password" and encrypt it using both Client's public key and Company's private key, in succession, and send it back to the client.</li><li>Client will decrypt the password. This process proves that Company sent the password and that only Client was able to read it.</li><li>Client will start communicating with Company by encrypting data using this password. Normal "symmetric" (password-based) encryption takes place from this point forward because it is much faster than using the public and private keys for everything. These keys were needed to enable Company to prove its identity and right to <tt>domain.com</tt> and to give client the password in a safe way.</li></ul><span style="font-weight: bold;">So, Are there Limitations to This Process?</span><br />This all sounds great - what are the down sides? There are a few.<br /><span style="font-weight: bold;">Key Length:</span>The statement that "only someone with the private key can decrypt something encrypted with the public key" is true so long as the private key cannot be "guessed". Hackers may try to do this by trying all possible private key combinations. Older "40bit" keys can be broken by trial and error if one has access to vast computer resources and a good amount of time. These days, keys used in SSL are 128bit or better. There are so many possible keys with 128bit that it would take significantly longer than the age of the universe to "guess" one.<br /><span style="font-weight: bold;">Trust:</span>While use of SSL ensures that your communications cannot be spied on, it comes down to trust to ensure that you are actually communicating with your intended company. This is reflected in the validation of company.com and your trust of the third party organization. Some "secure sites" do not bother to get a third party's approval and have their keys approved by "themselves". Others use third parties that are almost free and which spend very little effort in validating the company. In these cases, SSL provides you with no real assurance that you are really talking to your intended company and not some hacker trying to forge their identity to communicate with you in a manner in which you think you are safe.<br />For defensive use of the web, you should pay attention to warnings generated by SSL when you connect to secure sites. Such warnings include "expired certificates", "domain name mismatches" - where the domain name presented by the company is different than the one to which your are connecting, and "non trusted certificates" - where the public key (certificate) presented by the company was not validated by a third party that your computer trusts. In all of these cases, you should be wary.Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com1tag:blogger.com,1999:blog-1417917570575260537.post-38077745017050595622007-04-06T10:42:00.000+05:302007-04-06T10:49:22.703+05:30New Specs for Next-Generation Blu-ray Players<strong>Blu-ray Disc Association clarifies what new specs, due later this year, mean for owners of current Blu-ray players.</strong><br />Reports that your newly purchased Blu-ray Disc player will be obsolete by October are greatly exaggerated.<br />While it is true that the Blu-ray Disc Association recently set new minimum specifications for players produced after October 31--as we first outlined in our "High-Def Video Superguide"-those specifications only expand on the capabilities already present in existing players.<br />I spoke with Andy Parsons, chair of the U.S. promotion committee for the Blu-ray Disc Association, to clarify some of the common misconceptions.<br />All current Blu-ray Disc players support the BD-Java spec. (BD-Java is the programming language used to design the menus and present interactive content on a Blu-ray Disc.) In fact, says Parsons, this was a requirement from the get-go: "All players introduced since day one must support BD-Java."<br />Already, movie titles like Chicken Little and The League of Extraordinary Gentlemen are taking advantage of BD-Java's capabilities; in both of those cases, the movie discs offer interactive games.<br />If BD-Java is shipping today, why the confusion? "This fall," explains Parsons, "is the end of a grace period. Any new Blu-ray Disc player model introduced after October 31 must now fully comply with the full range of existing Blu-ray Disc player specifications."<br /><br /><strong>Blu-ray's New Specs</strong><br />The new specification requirements will enable many cool, long-promised Blu-ray Disc features that will boost Blu-ray's competitiveness in the interactivity realm with archrival HD DVD on players produced after the October 31 deadline.<br />These features include mandatory minimum storage requirements of 256MB for stand-alone players and 1GB for BD Live-connected players. (BD Live players can download additional entertainment content from the Internet, and will also require an ethernet connection.) All players will also need to support on-demand picture-in-picture via a secondary video stream (which could be accomplished via one video decoder or two, depending on how the real-time video is encoded); in addition, the players must support secondary audio mixing for mixing sound effects generated within the player with the soundtrack of the film.<br />"What's caused the confusion is that BD-Java will be utilized to implement these new capabilities. It's not that this is a new version of Java, it's just the code that will be used to run these features," Parsons says.<br /><br /><strong>HD DVD's Requirements</strong><br />In contrast, HD DVD already has a minimum storage requirement of 128MB of memory, an ethernet connection for connected interactivity, and a secondary video stream for on-demand picture-in-picture video. The memory requirement enables HD DVD players and titles to support persistent bookmarks that can stay in your player's memory, even after you eject the disc. And some titles, such as Mission: Impossible III, already have picture-in-picture director commentaries that you can activate at any time during the playback of the movie.<br />Parsons notes that these new capabilities "are not make-or-break features. Picture-in-picture is nice for on-screen directory commentaries and the like. But the fundamental functions of a Blu-ray player are already available in existing players.<br />"And," he stresses, "your existing Blu-ray player will continue to play future titles as it does today."<br /><br /><strong>What Current Players Won't Do</strong><br />Current Blu-ray players won't be able to play an on-demand picture-in-picture commentary, for example, that may come on a disc a year from now. Nor will they be able to connect to the Internet for future interactive functions that may be incorporated into the disc. But when that happens, Hollywood studio technologists have explained to me, they will likely program the disc in such a way that--if your player can't support the new feature--the option won't even show as available during playback.<br />The one possible exception to this among the currently shipping players: Sony's PlayStation 3, which ranked fourth in our recent high-definition player roundup. For one thing, the PS3 meets the technical requirements for BD Live Internet connectivity. According to Sony, the company is investigating and evaluating the implementation of BD Live, but it has not yet made any announcements of adopting and supporting BD Live.Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com1tag:blogger.com,1999:blog-1417917570575260537.post-34660821474277553232007-03-30T09:40:00.000+05:302007-03-30T10:05:34.932+05:30Get the most out of your laptop's battery<strong>Think small<br /></strong>The slower the components and the smaller the display, the less power needed to run the machine. A 12.1-inch screen uses 50 percent less juice than a 17-inch model, and getting a 4,200rpm hard drive instead of the 5,400rpm model can mean an extra 15 to 20 minutes of battery life.<br /><br /><strong>Control your power<br /></strong>Adjust your laptop's power settings to find a comfort zone where you're using as little power as possible with no interference in your computer tasks. The path to the control panel will vary according to your operating system and setup, but for Windows XP Home and Pro users, follow these steps: Go to Start > Control Panel > Performance And Maintenance > Power Options. Set the LCD screen to go off after 5 minutes of inactivity, let the hard drive stay active for 20 minutes, and store the system's contents in RAM when it shuts down. If your laptop goes to sleep too soon, adjust the settings.<br /><br /><strong>Dim all the lights<br /></strong>Your LCD's backlight uses up to 10 watts of power, a huge battery drain. Lower the screen's brightness to where it's comfortable to view without squinting. In addition to the Power Options settings detailed in tip 2, most laptops have convenient function keys for controlling brightness. Look for the function key with the brightness icon and a down arrow next to it. (This is the F6 key on many laptops.)<br /><br /><strong>Shut down unnecessary programs<br /></strong>When you're running your laptop on battery power, turn off devices and programs you don't need. When not connected to a wireless hot spot, turn off the Wi-Fi hardware. If you access wireless networks with a PC Card, remove it when not connected. Listening to music via the CD-ROM drive and watching DVDs are also big battery drains.Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com1tag:blogger.com,1999:blog-1417917570575260537.post-47990443465272596942007-03-08T15:34:00.000+05:302007-03-30T10:14:24.135+05:30How do Firewall Work<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://flickr.com/photo_zoom.gne?id=414405240&size=o"><img id="BLOGGER_PHOTO_ID_5039403167176544674" style="margin: 0pt 0pt 10px 10px; float: right; cursor: pointer;" alt="" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhcqUkgcl0DisOOU8LTHhy-Ksaic7dW8tePFHZBUbUILla1mRromNeA9fsU7jhbumovlBFd0f2H03vpGe2yN5FzxVa2DH9nKlEgWxAZRlLitH_eaRbIzhvKRhcm9uUeQciBLxBPttW8SYlM/s200/firewall.gif" border="0" /></a><a onclick="var s=s_gi(s_account);s.linkTrackVars='prop10';s.prop10='firewall.htm';void(s.tl(true,'o','Computer - Security Channel HP - Table Of Contents : Position 1'));" href="http://computer.howstuffworks.com/firewall.htm"> </a><span style="font-weight: bold;">Introduction to How Firewalls Work</span><br />If you have been using the Internet for any length of time, and especially if you work at a larger company and browse the Web while you are at work, you have probably heard the term <b>firewall</b> used. For example, you often hear people in companies say things like, "I can't use that site because they won't let it through the firewall."<br />If you have a fast Internet connection into your home (either a <a href="http://www.dsl-speed.org/dsl-speed.htm">DSL connection</a> or a <a href="http://en.wikipedia.org/wiki/Cable_modem">cable modem</a>), you may have found yourself hearing about firewalls for your <a href="http://en.wikipedia.org/wiki/Home_network">home network</a> as well. It turns out that a small home network has many of the same security issues that a large corporate network does. You can use a firewall to protect your home network and family from offensive Web sites and potential hackers.<br />Basically, a firewall is a barrier to keep destructive forces away from your property. In fact, that's why its called a firewall. Its job is similar to a physical firewall that keeps a fire from spreading from one area to the next. As you read through this article, you will learn more about firewalls, how they work and what kinds of threats they can protect you from.<br /><br /><span style="font-weight: bold;">What It Does<br /></span>A firewall is simply a program or hardware device that filters the information coming through the Internet connection into your private <a href="http://en.wikipedia.org/wiki/Computer_network">network</a> or <a href="http://www.ecs.com.tw/ECSWebSite/Index.aspx?MenuID=0&LanID=9">computer system</a>. If an incoming packet of information is flagged by the filters, it is not allowed through.<br />If you have read the article <a href="http://www.ciol.com/content/flavour/servertech/101071001.asp">How Web Servers Work</a>, then you know a good bit about how data moves on the Internet, and you can easily see how a firewall helps protect computers inside a large company. Let's say that you work at a company with 500 employees. The company will therefore have hundreds of computers that all have network cards connecting them together. In addition, the company will have one or more connections to the Internet through something like T1 or T3 lines. Without a firewall in place, all of those hundreds of computers are directly accessible to anyone on the Internet. A person who knows what he or she is doing can probe those computers, try to make FTP connections to them, try to make telnet connections to them and so on. If one employee makes a mistake and leaves a security hole, hackers can get to the machine and exploit the hole.<br />With a firewall in place, the landscape is much different. A company will place a firewall at every connection to the Internet (for example, at every T1 line coming into the company). The firewall can implement security rules. For example, one of the security rules inside the company might be:<br />Out of the 500 computers inside this company, only one of them is permitted to receive public FTP traffic. Allow FTP connections only to that one computer and prevent them on all others.<br />A company can set up rules like this for FTP servers, Web servers, Telnet servers and so on. In addition, the company can control how employees connect to Web sites, whether files are allowed to leave the company over the network and so on. A firewall gives a company tremendous control over how people use the network.<br /><br />Firewalls use one or more of three methods to control traffic flowing in and out of the network:<br /><ul><li><b>Packet filtering</b> - Packets (small chunks of data) are analyzed against a set of <b>filters</b>. Packets that make it through the filters are sent to the requesting system and all others are discarded.</li><li><b>Proxy service</b> - Information from the Internet is retrieved by the firewall and then sent to the requesting system and vice versa.</li><li><b>Stateful inspection</b> - A newer method that doesn't examine the contents of each packet but instead compares certain key parts of the packet to a database of trusted information. Information traveling from inside the firewall to the outside is monitored for specific defining characteristics, then incoming information is compared to these characteristics. If the comparison yields a reasonable match, the information is allowed through. Otherwise it is discarded.</li></ul><span style="font-weight: bold;">Making the Firewall Fit<br /><br /></span><ul><li><b>IP address:-</b>Each machine on the Internet is assigned a unique address called an <b>IP address</b>. IP addresses are 32-bit numbers, normally expressed as four "octets" in a "dotted decimal number." A typical IP address looks like this: 216.27.61.137. For example, if a certain IP address outside the company is reading too many files from a server, the firewall can block all traffic to or from that IP address.</li><li><b>Domain names :- </b>Because it is hard to remember the string of numbers that make up an IP address, and because IP addresses sometimes need to change, all servers on the Internet also have human-readable names, called <b>domain names</b>. For example, it is easier for most of us to remember www.howstuffworks.com than it is to remember 216.27.61.137. A company might block all access to certain domain names, or allow access only to specific domain names.</li><li><b>protocol :- </b>The <b>protocol</b> is the pre-defined way that someone who wants to use a service talks with that service. The "someone" could be a person, but more often it is a computer program like a Web browser. Protocols are often text, and simply describe how the client and server will have their conversation. The <b>http</b> in the Web's protocol. Some common protocols that you can set firewall filters for include:</li></ul><ol><li><b>IP</b> (Internet Protocol) - the main delivery system for information over the Internet</li><li><b>TCP</b> (Transmission Control Protocol) - used to break apart and rebuild information that travels over the Internet</li><li><b>HTTP</b> (Hyper Text Transfer Protocol) - used for Web pages</li><li><b>FTP</b> (File Transfer Protocol) - used to download and upload files</li><li><b>UDP</b> (User Datagram Protocol) - used for information that requires no response, such as streaming audio and video</li><li><b>ICMP</b> (Internet Control Message Protocol) - used by a router to exchange the information with other routers</li><li><b>SMTP</b> (Simple Mail Transport Protocol) - used to send text-based information (e-mail)</li><li><b>SNMP</b> (Simple Network Management Protocol) - used to collect system information from a remote computer</li><li><b>Telnet</b> - used to perform commands on a remote computer</li></ol>A company might set up only one or two machines to handle a specific protocol and ban that protocol on all other machines.<br /><ul><li><b>Ports :- </b>Any server machine makes its services available to the Internet using numbered <b>ports</b>, one for each service that is available on the server (see How Web Servers Work <span style="text-decoration: underline;"></span>for details). For example, if a server machine is running a Web (HTTP) server and an FTP server, the Web server would typically be available on port 80, and the FTP server would be available on port 21. A company might block port 21 access on all machines but one inside the company.</li><li>Specific words and phrases - This can be anything. The firewall will <b>sniff</b> (search through) each packet of information for an exact match of the text listed in the filter. For example, you could instruct the firewall to block any packet with the word "X-rated" in it. The key here is that it has to be an exact match. The "X-rated" filter would not catch "X rated" (no hyphen). But you can include as many words, phrases and variations of them as you need.</li></ul>Some operating systems come with a firewall built in. Otherwise, a software firewall can be installed on the computer in your home that has an Internet connection. This computer is considered a <b>gateway</b> because it provides the only point of access between your home network<span style="text-decoration: underline;"> </span>and the Internet.<br />With a hardware firewall, the firewall unit itself is normally the gateway. A good example is the Linksys Cable/DSL router. It has a built-in Ethernet card and hub. Computers in your home network connect to the router, which in turn is connected to either a cable or DSL modem. You configure the router via a Web-based interface that you reach through the browser on your computer. You can then set any filters or additional information.<br /><br /><p><strong>What It Protects You From </strong><br />There are many creative ways that unscrupulous people use to access or abuse unprotected computers: </p><ul><li><strong>Remote login </strong>- When someone is able to connect to your computer and control it in some form. This can range from being able to view or access your files to actually running programs on your computer. </li><li><strong>Application backdoors</strong> - Some programs have special features that allow for remote access. Others contain bugs that provide a backdoor, or hidden access, that provides some level of control of the program.</li><li><strong>SMTP session hijacking</strong> - SMTP is the most common method of sending e-mail over the Internet. By gaining access to a list of e-mail addresses, a person can send unsolicited junk e-mail (spam) to thousands of users. This is done quite often by redirecting the e-mail through the SMTP server of an unsuspecting host, making the actual sender of the spam difficult to trace.</li><li><strong>Operating system bugs</strong> - Like applications, some operating systems have backdoors. Others provide remote access with insufficient security controls or have bugs that an experienced hacker can take advantage of. </li><li><strong>Denial of service </strong>- You have probably heard this phrase used in news reports on the attacks on major Web sites. This type of attack is nearly impossible to counter. What happens is that the hacker sends a request to the server to connect to it. When the server responds with an acknowledgement and tries to establish a session, it cannot find the system that made the request. By inundating a server with these unanswerable session requests, a hacker causes the server to slow to a crawl or eventually crash.</li><li><strong>E-mail bombs </strong>- An e-mail bomb is usually a personal attack. Someone sends you the same e-mail hundreds or thousands of times until your e-mail system cannot accept any more messages. </li><li><strong>Macros </strong>- To simplify complicated procedures, many applications allow you to create a script of commands that the application can run. This script is known as a macro. Hackers have taken advantage of this to create their own macros that, depending on the application, can destroy your data or crash your computer. </li><li><strong>Viruses </strong>- Probably the most well-known threat is computer viruses. A virus is a small program that can copy itself to other computers. This way it can spread quickly from one system to the next. Viruses range from harmless messages to erasing all of your data. </li><li><strong>Spam </strong>- Typically harmless but always annoying, spam is the electronic equivalent of junk mail. Spam can be dangerous though. Quite often it contains links to Web sites. Be careful of clicking on these because you may accidentally accept a cookie that provides a backdoor to your computer. </li><li><strong>Redirect bombs </strong>- Hackers can use ICMP to change (redirect) the path information takes by sending it to a different router. This is one of the ways that a denial of service attack is set up. </li><li><strong>Source routing </strong>- In most cases, the path a packet travels over the Internet (or any other network) is determined by the routers along that path. But the source providing the packet can arbitrarily specify the route that the packet should travel. Hackers sometimes take advantage of this to make information appear to come from a trusted source or even from inside the network! Most firewall products disable source routing by default. </li></ul><p>Some of the items in the list above are hard, if not impossible, to filter using a firewall. While some firewalls offer virus protection, it is worth the investment to install anti-virus software on each computer. And, even though it is annoying, some spam is going to get through your firewall as long as you accept e-mail. </p><p>The level of security you establish will determine how many of these threats can be stopped by your firewall. The highest level of security would be to simply block everything. Obviously that defeats the purpose of having an Internet connection. But a common rule of thumb is to block everything, then begin to select what types of traffic you will allow. You can also restrict traffic that travels through the firewall so that only certain types of information, such as e-mail, can get through. This is a good rule for businesses that have an experienced network administrator that understands what the needs are and knows exactly what traffic to allow through. For most of us, it is probably better to work with the defaults provided by the firewall developer unless there is a specific reason to change it. </p><p>One of the best things about a firewall from a security standpoint is that it stops anyone on the outside from logging onto a computer in your private network. While this is a big deal for businesses, most home networks will probably not be threatened in this manner. Still, putting a firewall in place provides some peace of mind. </p><p><strong>Proxy Servers and DMZ</strong></p><p>A function that is often combined with a firewall is a proxy server. The proxy server is used to access Web pages by the other computers. When another computer requests a Web page, it is retrieved by the proxy server and then sent to the requesting computer. The net effect of this action is that the remote computer hosting the Web page never comes into direct contact with anything on your home network, other than the proxy server. </p><p>Proxy servers can also make your Internet access work more efficiently. If you access a page on a Web site, it is cached (stored) on the proxy server. This means that the next time you go back to that page, it normally doesn't have to load again from the Web site. Instead it loads instantaneously from the proxy server. </p><p>There are times that you may want remote users to have access to items on your network. Some examples are: </p><ul><li>Web site </li><li>Online business </li><li>FTP download and upload area </li></ul><p>In cases like this, you may want to create a DMZ (Demilitarized Zone). Although this sounds pretty serious, it really is just an area that is outside the firewall. Think of DMZ as the front yard of your house. It belongs to you and you may put some things there, but you would put anything valuable inside the house where it can be properly secured. </p><p>Setting up a DMZ is very easy. If you have multiple computers, you can choose to simply place one of the computers between the Internet connection and the firewall. Most of the software firewalls available will allow you to designate a directory on the gateway computer as a DMZ. </p><p>Once you have a firewall in place, you should test it. A great way to do this is to go to www.grc.com and try their free Shields Up! Security test. You will get immediate feedback on just how secure your system is!</p>Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com2tag:blogger.com,1999:blog-1417917570575260537.post-22065107618387424702007-02-25T10:31:00.000+05:302007-02-28T12:16:05.051+05:305 Windows Vista Tips<span style="font-weight: bold;">Access More Media with Spotlight. </span><br />Almost all <a href="http://www.microsoft.com/windowsvista/versions/default.mspx">versions of Windows </a><a href="http://www.microsoft.com/windowsvista/">Vista</a> come with enhanced Windows <a href="http://www.microsoft.com/windowsxp/mediacenter/default.mspx">Media Center</a> functionality, which allows you to create, store, organize, edit, and view personal and public media. The Start menu choices in Windows Media Center in Windows Vista are <b>Pictures</b> + <b>Video</b>, <b>Movies</b>, <b>TV</b>, <b>Music</b>, <b>Spotlight</b>, <b>Tools</b>, and <b>Tasks</b>. If your computer is outfitted with the <a href="http://www.microsoft.com/technet/windowsvista/evaluate/hardware/entpguid.mspx">proper hardware</a>, you can turn your PC into a complete home theater system, including a DVD player and recorder, a movie theater, a movie studio, a television, a personal video recorder, a jukebox, a music server, and a photo library.<br /><div style="text-align: left;">One feature of Windows Media Center really stands out for me though: the <b>Spotlight</b>. As you can see below, there are currently two choices under <b>Spotlight</b>, <b>More Programs</b> and <b>Online Spotlight</b>. <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://www.flickr.com/photo_zoom.gne?id=400387539&size=o"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgao1dVmewviMVBJCa5HvlMN7U_KOGh4LZc-VHE1EL4C1JhE91xYnfryO_suu2LiHgpg64KmMu9Nlvbgh7rlf3GBUjHg_Rcgjdq-98aL9l_65ZkcebPmMUInUiswlvgXwwIZuYfMl1C2ePk/s200/400387539_14ce577c09_t.jpg" alt="" id="BLOGGER_PHOTO_ID_5035386524740577234" border="0" /></a> From <b>More Programs</b>, you can play games such a s <b>Chess Titans</b>, <b>Spider Solitaire</b>, and <b>FreeCell</b>, or select <b>Online Spotlight</b> to gain access to online media. You can also add applications or services to your More Programs area for easy discoverability.<br /></div>In the following image, you can see Online Spotlight in Windows Media Center. As you move the mouse—or click with your remote control—over each choice, the icon comes to the forefront and an explanation is offered regarding what the service or choice actually does. In this example, you can use <b>MSN Remote Record Service</b> to schedule your TV recordings from anywhere in the world, as long as you have access to the Internet! This particular group of icons is available from <b>Showcase</b>. <a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://www.flickr.com/photo_zoom.gne?id=400387544&size=o"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhDmk9Kff3Cu_Vmnf365_g_VD7PE3kbHY3VVHzQ1lfjkM-KRlPF6qAAgsjQTkYSCtq3eiz0v8FWxtCXTGo9FSm_xU4p4ljTPyjaKi-5YOVZ0gsXnnXrecZajv1XR3_FknjVl5TOk_yNsyu0/s200/400387544_8421449592_t.jpg" alt="" id="BLOGGER_PHOTO_ID_5035387748806256610" border="0" /></a> Here are a few more things you can do with Online Spotlight, including but not limited to:<br /><ul><li>Access free television shows, Internet radio, news, movie trailers, podcasts, and videos from AOL, Yahoo!, Reuters, MSN TV Today, and ABC. </li><li>Download and purchase movies and TV content through subscription services such as Movielink, TVTonic, CinemaNow, and Comedy Central. The following figure shows Movielink.<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://www.flickr.com/photo_zoom.gne?id=400387545&size=o"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgIGEgvbYaAmjk6gNMvpxosCNz_Dkt2twEOMPv8JnDLY7C3IK-Gm_vyuBkJF2YuwoCfyIgOoHz-CmqRwQOr2tW6RSzOxrAbPaY1biUfbeTP6ES3vbj7nfSKDjG790gVb4oX-OXN2vJQyFNw/s200/3.jpg" alt="" id="BLOGGER_PHOTO_ID_5035388680814159858" border="0" /></a> </li><li>Purchase, Save, and/or Play Music from Napster, Satellite Radio, and MTV Overdrive and from VH1, MusicMatch, and Live365.com.</li><li>Share photos with Kodak Share and view image collections from Gallery Player.</li><li>Play games alone or with others from Gaming on Demand and DISCover Games.</li><li>Burn DVDs of your favorite TV shows from PrimeTime and ARcSoft QuickDVD.</li></ul>Spotlight makes it clear though: If you've been putting off getting an "always on" connection to the Internet, now's the time. Windows Media Center in Windows Vista will work to its full potential if an always-on connection is available.<br /><br /><b>View and Manage Pictures and Videos with Photo Gallery</b><br />Check out the new Photo Gallery in Windows Vista. You can sort pictures and videos by keywords, tags, the date the pictures or video were taken, ratings, and other metadata. You can even create Search Folders that contain up-to-date and "live" data, which changes each time you open the folder. You can create your own metadata to totally organize your photos and videos using any type of organizational set you'd like.<br />Windows Photo Gallery is shown here with March 2006 selected for viewing, and the image of the dog is highlighted. In using the hover preview, notice how the image comes to the forefront and information about the image is shown.<a href="http://www.flickr.com/photo_zoom.gne?id=400387547&size=o"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjcPQq4MnzmlEAvvSJmOdCR5TuAw4zfSi1XmbwLysw4PzXBAvxCT32dUAP7C_k0nmagaZydVGbQbvl01MMmbKZU88CKIOVGUrgr5NGoaYKsHxUDRuKAYfm6Al8VFyOzAg_vE3RJqMnsXLuL/s200/4.jpg" alt="" id="BLOGGER_PHOTO_ID_5035389273519646722" border="0" /></a> I prefer to sort my photos by their folder names. As you can see in the next image, there are multiple named folders and subfolders. Selecting any folder on the left produces its contents on the right. Using the mouse to hover over any picture offers information about that picture as well. In this image, the folder My Pictures is selected, and two of the subfolders are showing, Nikko and Photo Album. On the right side, you can see there are 719 photos in the My Pictures folder.<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://www.flickr.com/photo_zoom.gne?id=400387550&size=o"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj9McJHzhsCcNrd1jm8IrIUtlPWWksh9TQ0VRJdebHz28wJgFjGX4VYk1PGP6IQ0NwSIaCuJLvZ-aUVEQFjnxCZ9gKBeNO9uxjiDmViqGD4PkI0n4zOOI3HpuWAvO_l743Z7tBLYkSJJGIx/s200/5.jpg" alt="" id="BLOGGER_PHOTO_ID_5035390055203694610" border="0" /></a> If you choose to sort folders by name, organize your images by subject such as Home, Weddings, Vacations, Friends, Family, Special Events, and Pets, and create subfolders for each. You can then browse images by their subject category. Because images from digital cameras automatically register the date taken in the metatag, it's just as easy to then organize the images by date taken. You can do this with a simple click of the mouse.<br /><br /><span style="font-weight: bold;">Improve Your Media Experience with Windows Media Player 11</span><br />Windows Media Player 11 is another new feature included in Windows Vista. Windows Media Player 11 has a deeply integrated music library for both online and offline content, with an interface that looks more like a Web site than computer application. And with a new integrated feel, Windows Media Player 11 makes online, network, and offline content indistinguishable. Windows Media Player 11 also connects to additional hardware easily and offers easy-to-use tools for following the process of any task (downloading music, burning CDs, synching music, or streaming video, just to name a few). You can learn more about Windows Media Player 11 at this <a href="http://www.microsoft.com/windowsvista/experiences/nextgenplayer.mspx">Windows Vista Community Web page</a>. <p>One of my favorite additions to Windows Media Player 11 is the Global and Sync Status tools. In older versions of Windows Media Player, you never really knew what was going on during a task. Isn't buffering finished yet? How's that sync going? Will all of this fit on a CD? And which songs can I put on there, based on the song's license? And, of course, why won't this song sync to my MP3 player? Windows Media Player 11 has ended these aggravations with Global Status and Sync Status.</p> <p>In addition to the new status features, there are new search features too. With WordWheel, for instance, you can type part of the artist's name, song title, or genre—whatever you can remember—into the Search bar. The Library "prunes" through your entire collection with a query across relevant fields and offers up what options most closely relate to your entry. Here's an example. I've typed PA in the Search bar and selected Artist. There are four artists in my library whose name begins with Pa. The more letters I type, the shorter the list gets. It's a "smart" search and will change the way to locate data, including all media, on your computer forever.</p> <p><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://www.flickr.com/photo_zoom.gne?id=400387551&size=o"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiuoXTPfvGDvTBv-PxSAyGtxg5i6RhWCTVxFk4_1yD800fVcTlsf_-F2ft5c7VmWdV3rku2rMpeEjH4GfjMoItV78LyEyQvmirwKwwEiESDlJ9oqENdYAutGiZJoUILEMHKORH_o2JYHHLn/s200/6.jpg" alt="" id="BLOGGER_PHOTO_ID_5035391038751205410" border="0" /></a></p> <span style="font-weight: bold;font-size:100%;" >Organize and Find Data with New Search Tools<br /></span><p>Speaking of new search features—using Search Tools and Search Folders you can locate all of the data on your PC, including the data you have in Windows Mail, Windows Media Player 11, Windows Photo Gallery, and your personal files and folders quickly and easily. No more having to remember where you've stored a file. Those days are over. Now, you only need to remember something about what you're looking for, such as a word contained in a document, part of the title of a song or album, or the month or day a picture was taken. This search feature provides the same functionality detailed in the previous section.</p> <p>You can also help the new Search Tools provide more accurate results by adding your own tags to data. For example, you can add a keyword to all documents related to a specific project after you save them to your computer. Later, just search for the project keyword in the Quick Search box on the Start menu, and all the project-related pictures will be displayed. This search works with any type of data, including music, pictures, and videos.</p> <p> </p><p>Another new search tool in Windows Vista is Search Folders. An easy way to get started with Search Folders is to click Start, and then click Search. The Search window opens, and you will type your search keyword(s). You can then save that search to your hard drive. That Search Folder becomes an excellent tool for finding up-to-date information about the files on your computer that you create, save, and search for often. Opening a saved Search Folder instantly runs that saved search again (behind the scenes), displaying brand new results immediately. Here's an example:<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://www.flickr.com/photo_zoom.gne?id=400388656&size=o"><img style="margin: 0px auto 10px; display: block; text-align: center; cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj5pMpvm-RowPQOMjbjiyEZ55xbJkqTMftHsOxvT62jraBLnsne56MHWRjzaqCy6ZmbpGXasJmVPqTElu_6TdWS8l8gJPmMhVnu2tvFSkHNYT0WN4WxcqNAm5jxXjIyNYo8uxJMe9OJI2Mc/s200/400388656_2a4ebb1abf_t.jpg" alt="" id="BLOGGER_PHOTO_ID_5035391846205057074" border="0" /></a></p>In this image, I've searched for "Jennifer." The search results include a contact, an Office Word document, a folder, several images, a Journal page, and a shortcut. Now all I have to do is click the item and gain access. As shown on the left side of this image, a Saved Searches folder also exists. When you click that folder you can see all of your saved searches as well as default saved search folders. The default folders are already set up and include automatic searches for <b>Last 7 Days E-Mail</b>, <b>Favorite Music</b>, <b>Last 30 Days Documents</b>, and more. As noted earlier, these new search features will change the way you use your computer forever.<br /><br /><span style="font-weight: bold;">Manage Your PC with New Choices in Control Panel</span><br />The Control Panel in Windows Vista offers many new features too, as you can see in the screenshot below. Although each of the new items in Control Panel merit their own stand-alone articles, I'll introduce a few of the new items briefly.<br />New Control Panel items include:<br /><ul><li><b>Network Center</b>. You can use this feature to view your Network Map and uncover connectivity problems, configure basic security settings, and view network details.</li><li><b>Parental Controls</b>. You can use Parental Controls to enable, configure, and manage the new parental controls in Windows Vista.</li><li><b>Pen and Input Devices</b>. You can use this feature to configure and manage alternate input devices including pens and input panels.</li><li><b>Sidebar Properties</b>. With this feature, you can configure and manage how the Windows Vista sidebar appears on the interface.</li><li><b>Sync Center</b>. You can use Sync Center to manage synched hardware such as PDAs, portable media players, and other devices.</li><li><b>Text to Speech</b>. With Text to Speech, you can set up, train, and run speech recognition, and to configure and run text to speech translation.</li><li><b>Windows Defender</b>. With this functionality, you can check for unwanted or harmful software, scan your computer, view quarantined items, and visit the Windows Defender Web site.</li><li><b>Windows SideShow</b>. You can use the Windows SideShow to connect a secondary display that accesses information like e-mail or media from a mobile phone or other mobile device. And you can use Windows SideShow to check your mail while you are away from your computer.</li></ul>Windows Vista truly is a giant leap into the technological future. Beyond the sleek, new, Web-like interface, new Windows Media Center 11 features, the increased security, hands-off approach to keeping your computer safe, and Windows Vista ease-of-use, there are a thousand things to keep you electrified, excited, and enthused. Just be careful, you may end up like me, doing more playing than working!Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com4tag:blogger.com,1999:blog-1417917570575260537.post-36900803686486332912007-02-22T17:54:00.000+05:302007-02-23T17:40:40.116+05:30How MP3 Files Work<strong>Introduction to How MP3 Files Work : </strong><br />The MP3 movement is one of the most amazing phenomena that the music industry has ever seen. Unlike other movements - for example, the introduction of the <a href="http://en.wikipedia.org/wiki/Compact_audio_cassette">cassette tape </a>or the <a href="http://en.wikipedia.org/wiki/CD-ROM">CD</a> - the MP3 movement started not with the industry itself but with a huge audience of music lovers on the <a href="http://en.wikipedia.org/wiki/Internet">Internet</a>. The MP3 format for digital music has had, and will continue to have, a huge impact on how people collect, listen to and distribute music.<br /><br /><br /><p><a href="http://flickr.com/photo_zoom.gne?id=398686286&size=o"><img id="BLOGGER_PHOTO_ID_5034342924997060482" style="DISPLAY: block; MARGIN: 0px auto 10px; TEXT-ALIGN: center" alt="" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhIZQqVQfoWqonLvjuD2-MY76FaNhrOYPwfigDPwD3h_IPRfjb3D8bv5aIdZtNoS2YKeDTfe4hPgmMIoeMfDUsbzA6j0y9ytQWFNc8E7AcK3rxWmztzsR_-_5t8dxFW29BgaGvlimeeqQ1k/s200/mp3-cycle.gif" border="0" /></a>If you have ever wondered how MP3 files work, or if you have heard about MP3 files and wondered how to use them yourself, then this article is for you! In this article, you will learn about the MP3 file format and how you can start downloading, listening to and saving MP3 files onto CDs! </p><p><strong>The MP3 Format : </strong></p><p>If you have read <a href="http://express.howstuffworks.com/express-cd.htm">How CDs Work</a>, then you know something about how CDs store music. A CD stores a song as digital information. The data on a CD uses an uncompressed, high-resolution format. Here's what happens when a CD is created: </p><ul><li>Music is sampled 44,100 times per second. The samples are 2 bytes (16 bits) long.</li><li>Separate samples are taken for the left and right speakers in a stereo system.</li></ul>So a CD stores a huge number of bits for each second of music:<br /><b>44,100 samples/second * 16 bits/sample * 2 channels = 1,411,200 bits per second<br /></b>Let's break that down: 1.4 million bits per second equals 176,000 bytes per second. If an average song is three minutes long, then the average song on a CD consumes about 32 million bytes of space. That's a lot of space for one song, and it's especially large when you consider that over a 56K<a href="http://en.wikipedia.org/wiki/Modem"> modem</a>, it would take close to two hours to download that one song.<br />The MP3 format is a <a href="http://en.wikipedia.org/wiki/Data_compression">compression</a> system for music. The MP3 format helps reduce the number of bytes in a song without hurting the quality of the song's sound. The goal of the MP3 format is to compress a <b>CD-quality</b> song by a factor of 10 to 14 without noticably affecting the CD-quality sound. With MP3, a 32-megabyte (MB) song on a CD compresses down to about 3 MB. This lets you download a song in minutes rather than hours, and store hundreds of songs on your computer's <a href="http://en.wikipedia.org/wiki/Hard_disk">hard disk</a> without taking up that much space.<br /><br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://flickr.com/photo_zoom.gne?id=398724875&size=o"><img id="BLOGGER_PHOTO_ID_5034571717904918418" style="DISPLAY: block; MARGIN: 0px auto 10px; CURSOR: pointer; TEXT-ALIGN: center" alt="" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgrYVEkHDOI26S6bS1V0bqtJgnecQ3UYfbj2ved7Sva7J73TkZZ5TgtjMZV4nxcer2hGa3MJj3y_aDOmj2EULLl7fS529x2ZpHdLLDqMBVLbjFGEq7BF9VpHc-UB1VnxhOdTKnenlBWsjtI/s200/mp3-waves.gif" border="0" /></a>Is it possible to compress a song without hurting its quality? We use <a href="http://www.howstuffworks.com/question408.htm">compression algorithms for images</a> all the time. For example, a GIF file is a compressed image. So is a JPG file. We create <a href="http://www.howstuffworks.com/framed.htm?parent=mp3.htm&url=http://www.winzip.com/aboutzip.htm">Zip files</a> to compress text. So we are familiar with compression algorithms for images and words and we know they work. To make a good compression algorithm for sound, a technique called <b>perceptual noise shaping</b> is used. It is "perceptual" partly because the MP3 format uses characteristics of the <a href="http://www.howstuffworks.com/hearing.htm">human ear</a> to design the compression algorithm. For example:<br /><ul><li>There are certain sounds that the human ear cannot hear.</li><li>There are certain sounds that the human ear hears much better than others.</li><li>f there are two sounds playing simultaneously, we hear the louder one but cannot hear the softer one.</li></ul><p>Using facts like these, certain parts of a song can be eliminated without significantly hurting the quality of the song for the listener. Compressing the rest of the song with well-known compression techniques shrinks the song considerably -- by a factor of 10 at least. (If you would like to learn more about the specific compression algorithms, see the links at the end this article.) When you are done creating an MP3 file, what you have is a "<b>near CD quality</b>" song. The MP3 version of the song does not sound exactly the same as the original CD song because some of it has been removed, but it's very close. </p><p>From this description, you can see that MP3 is nothing magical. It is simply a file format that compresses a song into a smaller size so it is easier to move around on the Internet and store. <span style="FONT-WEIGHT: normal;font-size:100%;" ><span style="FONT-WEIGHT: bold"></span></span></p><p><span style="FONT-WEIGHT: normal;font-size:100%;" ><span style="FONT-WEIGHT: bold">Using the MP3 Format</span> </span></p><p><span style="FONT-WEIGHT: normal;font-size:100%;" >Knowing about the MP3 format isn't half as interesting as using it. The MP3 movement -- consisting of the MP3 format and the Web's ability to advertise and distribute MP3 files -- has done several things for music:</span></p><ul><li>It has made it easy for anyone to distribute music at nearly no cost (or <a href="http://www.howstuffworks.com/file-sharing.htm">for free</a>).</li><li>It has made it easy for anyone to find music and access it instantly.</li><li><div align="left">It has taught people a great deal about manipulating sound on a computer.<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://flickr.com/photo_zoom.gne?id=398724871&size=o"></div><br /><div align="center"><img id="BLOGGER_PHOTO_ID_5034573981352683426" style="DISPLAY: block; MARGIN: 0px auto 10px; CURSOR: pointer; TEXT-ALIGN: center" alt="" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJt6-lYJo5zEScI2haZ_wwOJ30OedfCY-H-jkc7A7oK3mzqlBMCxrOUlpR0OoZCdjlBuXJ_bKf6XO-e-i-YJpmo6s9jZ1tpN2BE0CPIFbNF5ehLBKtZ6dviu17luAHWwo9f43hxsvYkDzM/s200/mp3-player-download.gif" border="0" /></div><br /><p align="left"></a><span style="COLOR: rgb(51,0,51)">That third one was accidental but important. A big part of the MP3 movement is the fact that it has brought an incredible array of powerful tools to </span><span style="COLOR: rgb(51,0,51)">desktop computers</span><span style="COLOR: rgb(51,0,51)"> </span>and given people a reason to learn how they work. Because of these tools, it is now extremely easy for you to:</p></li><li><p align="left">Download an MP3 file from a Web site and play it</p></li><li><p align="left">Rip a song from a music CD and play it directly or encode it as an MP3 file </p></li><li><p align="left">Record a song yourself, convert it to an MP3 file and make it available to the world </p></li><li><p align="left">Convert MP3 files into CD files and create your own audio CDs from MP3 files on the Web </p></li><li><p align="left">Rip songs off of various music CDs and recombine them into your own custom CDs</p></li><li><p align="left">Store hundreds of MP3 files on data CDs</p></li><li>Load MP3 files into tiny portable players and listen to them wherever you go</li></ul><p>To do all of these amazing things, all you need is a computer with a <a href="http://www.howstuffworks.com/sound-card.htm">sound card</a> and <a href="http://www.howstuffworks.com/speaker.htm">speakers</a>, an Internet connection, a <a href="http://www.howstuffworks.com/cd-burner.htm">CD-R drive</a> to create CDs and an <a href="http://www.howstuffworks.com/mp3-player.htm">MP3 player</a>. If you simply want to download MP3 files from the Web and listen to them, then all you need is a computer with a sound card and speakers and an Internet connection - things you probably already have!<br />Let's look at many of the different things you can do with MP3 files and the software that makes it possible. </p><p><strong>Downloading and Listening</strong></p><p>If you would like to download and then listen to MP3 files on your computer, then you need:</p><ul><li>A computer</li><li>A <a href="http://www.howstuffworks.com/sound-card.htm">sound card</a> and <a href="http://www.howstuffworks.com/speaker.htm">speakers</a> for the computer (If your computer has speakers, it has a sound card.)</li><li>An Internet connection (If you are browsing the Web to read this article, then you have an Internet connection and it is working fine.)</li><li>An MP3 player (a software application you can download from the Web in 10 minutes)</li></ul><p>If you have recently purchased a new computer, chances are it already has software that can play MP3 files installed on its hard disk. The easiest way to find out if you already have an MP3 player installed is to download an MP3 file and try to double-click on it. If it plays, you are set. If not, you need to download a player, which is very easy to do.<br />There are literally thousands of sites on the Web where you can download MP3 files. (<a href="http://www.howstuffworks.com/search.php?terms=mp3+download" target="_blank">Click here</a> to do a search for MP3 download sites.) Go to one of these sites, find a song and download it to your hard disk (most MP3 sites let you either listen to the song as a streaming file or download it -- you want to download). Most songs range between 2 and 4 MB, so it will take 10 to 15 minutes unless you have a high-speed Internet connection. Once the song has finished downloading, try to double-click on the file and see what happens. If your computer plays it, then you are set. </p><p>If you find that you cannot play it, then you need to download an MP3 player. There are dozens of players available, and most of them are free or shareware (shareware is extremely inexpensive). One of the most popular is WinAmp, which you can download from <a href="http://www.winamp.com">www.winamp.com</a>.</p><p><a href="http://flickr.com/photo_zoom.gne?id=398724880&size=o"><img id="BLOGGER_PHOTO_ID_5034578014326974402" style="DISPLAY: block; MARGIN: 0px auto 10px; CURSOR: hand; TEXT-ALIGN: center" alt="" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgZfPN4_9YkRoUmYZz-Dz6RnmoNKs8jpyQQnl_O1A8nX3mjnZmpkXuxC8HvUrkTR1EIJFbKjdAwFx1RdLYUdJrYL4haWgO0PSvmZD2XBJlaLZ8eNiyCFFFfzVeMHdDZpwuadMckc9MECPeE/s200/mp3-winamp.gif" border="0" /></a></p><p>computer. Many people have hundreds of songs they have collected, and they create jukebox-like playlists so that their computer can play them all day long!</p><p><strong>Taking the Files With You</strong></p><p>Many people who start collecting MP3 files find that they want to listen to them in all kinds of places. Small, <a href="http://www.howstuffworks.com/mp3-player.htm">portable MP3 players</a> answer this need. These players are like portable cassette players except that they are smaller.<br />These players plug into your computer's <a href="http://www.howstuffworks.com/parallel-port.htm">parallel</a>, FireWire or <a href="http://www.howstuffworks.com/usb.htm">USB port</a> to transfer the data, and a software application lets you transfer your MP3s into the player by simply dragging the files. See <a href="http://www.howstuffworks.com/mp3-player.htm">How MP3 Players Work</a> for details.</p><p><strong>Creating Your Own</strong></p><p>f you have a CD collection and would like to convert songs from your CDs into MP3 files, you can use ripper and encoder software to do just that. A ripper copies the song's file from the CD onto your hard disk. The encoder compresses the song into the MP3 format. By encoding songs, you can play them on your computer or take them with you on your MP3 player.</p><p><a href="http://www.howstuffworks.com/framed.htm?parent=mp3.htm&url=http://www.winappslist.com/multimedia/mp3_encoders.htm">This page</a> contains a list of some rippers and encoders.</p><p><strong>Writing MP3s to CDs </strong></p><p>If you have a <a href="http://www.howstuffworks.com/cd-burner.htm">writable CD drive</a> in your computer, there are two ways to save your MP3 files on a CD:</p><ul><li>You can write the MP3 files themselves onto a data CD in order to save them and clear some space on your hard disk. You can then listen to the files on any computer. Some car stereos and DVD players now let you play data-encoded MP3s, too.</li><li>You can convert (decode) your MP3 files into full-size CD tracks and then save them to an audio CD. This allows you to listen to your MP3 files on any CD player.</li></ul><p>WinAmp has a plug-in that creates full-size WAV files from MP3 files, and some of the encoders will also decode. Once you have the full-size CD tracks, then the software that comes with your <a href="http://www.howstuffworks.com/cd-burner.htm">CD-R drive</a> will let you create an audio CD easily.<br />The <a href="http://www.howstuffworks.com/framed.htm?parent=mp3.htm&url=http://www.cdrfaq.org">CD-Recordable FAQ</a> is an excellent source of information on getting data and music onto a CD. </p><p><strong>Distributing Original Music</strong></p><p>If you are an artist who is recording music at home or in a small studio, you can use MP3 files and the Web to distribute your music to an extremely large audience. The first step is to create a song, either on a <a href="http://www.howstuffworks.com/cassette.htm">cassette tape</a>, <a href="http://www.howstuffworks.com/question55.htm">minidisc</a> or <a href="http://www.howstuffworks.com/cd.htm">CD</a>. If it is on a CD, you can use the ripper and encoder tools described in the previous section to create an MP3 file. If it is on a cassette (or minidisc), you can connect the output of your cassette (or minidisc) deck to the line-in or <a href="http://www.howstuffworks.com/question309.htm">microphone</a> jack of your sound card and record the music digitally on your computer. Then you can encode that file to create the MP3.<br />Once you have an MP3 file in hand, you have two distribution options: </p><ul><li>You can go to an MP3-distribution site and let them distribute your music. The advantage of this approach is that large MP3-distribution sites gets millions of visitors every month, so the potential audience you can reach is very large.<br />Music.Download.com is expected to launch in 2004. You'll be able to upload MP3s here and share them with a lot of people. In the meantime, you can receive updates by submitting your e-mail address. </li><li>You can create your own Web site for your music or band and promote the site yourself. This gives you more control and individuality, but requires you to get the word out on your own. See <a href="http://www.howstuffworks.com/web-page.htm">How Web Pages Work</a> for details on creating and hosting your own Web site.</li></ul><p>One good option is to make your MP3 files available on a large Web site and then link to the download area from your band's Web site. This lets you get the best of both worlds, and you can take advantage of the larger site's servers for those big MP3 files.</p>Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com0tag:blogger.com,1999:blog-1417917570575260537.post-69341457980792945572007-02-15T16:31:00.000+05:302007-02-23T14:57:32.389+05:30Tighten Microsoft Windows to Improve SecurityWindows has security holes. <a href="http://www.microsoft.com/">Microsoft</a> Windows XP Service Pack 2 (released in August 2004) is much more secure than Windows XP-SP1, XP, 2000, ME, 98 or 95. For an introduction to Internet security for home and SOHO end users, see our <a href="http://www.firewallguide.com/overview.htm">Overview</a> page. For this week's top Internet security and privacy topics, see our <a href="http://www.firewallguide.com/newsletter.htm">Newsletter</a> page.<br /><ul><li>Upgrade to Windows XP Service Pack 2. Turn on automatic updates and turn on the Windows firewall (until you replace it with a better one). Turn off file and printer sharing if you do not use these features. If you want or need to do a clean install, see our <a href="http://www.firewallguide.com/installation.htm">Installation</a> page.</li><li>Replace Internet Explorer with <a href="http://www.mozilla.org/products/firefox/">Firefox</a> and Outlook Express with a more secure email client like <a href="http://www.mozilla.org/products/thunderbird/">Thunderbird</a>. Also consider signing up with an ISP and/or email service that provides online spam, virus and content filters for two levels of protection, see our <a href="http://www.firewallguide.com/broadband.htm">Broadband</a> and <a href="http://www.firewallguide.com/hosting.htm">Secure Website & Email Hosting</a> pages. </li><li>Turn off the Windows XP firewall and replace it with software and hardware firewalls for two levels of protection, see our <a href="http://www.firewallguide.com/software.htm">firewall software</a>, <a href="http://www.firewallguide.com/hardware.htm">wired</a> and <a href="http://www.firewallguide.com/wireless.htm">wireless</a> router pages. Be sure to test them after installation, see our <a href="http://www.firewallguide.com/test.htm">testing</a> page.</li><li>Install <a href="http://www.firewallguide.com/anti-virus.htm">anti-virus</a> and <a href="http://www.firewallguide.com/spyware.htm">anti-spyware</a> software. Also consider using <a href="http://www.firewallguide.com/anti-trojan.htm">anti-trojan</a>, <a href="http://www.firewallguide.com/spam.htm">anti-spam</a>, <a href="http://www.firewallguide.com/phishing.htm">anti-phishing</a> and <a href="http://www.firewallguide.com/privacy.htm">privacy</a> software. Turn on automatic updating and/or check for updates of malware definition files yourself at least once a week.</li><li><strong>Tighten Windows </strong><a href="http://www.lbl.gov/ITSD/Security/systems/wxp-security-checklist.html">Checklist for Securing Windows XP Pro</a>, Lawrence Berkeley Nat'l Lab<br />TomCat's <a href="http://www.tom-cat.com/security.html">Secure Your Home Computer</a><br /><a href="http://www.tweakhound.com/xp/security/page_1.htm">Securing Windows XP</a>, Wall & Vaughan, TweakHound<br /><a href="http://labmice.techtarget.com/articles/winxpsecuritychecklist.htm">Windows XP Security Checklist</a>, LabMice.net<br />Consider using a product like the <a href="http://www.computersecuritytool.com/">Computer Security Tool</a> to help you tighten Windows (trial version available).</li><li><a href="http://www.michaelhorowitz.com/backupclass.html">Backup</a> your files at least weekly including documents, music, photos...</li><li>If you are using a dial-up Internet connection, consider moving to <a href="http://www.firewallguide.com/broadband.htm">DSL or cable</a> to make it easier and faster to use the automatic update features of Windows, anti-virus, and other security and privacy software.</li></ul><p>Thank for <a href="http://www.firewallguide.com">Home PC Firewall Guide</a>.</p>Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com3tag:blogger.com,1999:blog-1417917570575260537.post-34833555517963625062007-02-10T18:53:00.000+05:302007-11-30T10:11:28.922+05:30Boot sector virus repair<strong>What is a boot sector?</strong><br />All disks and hard drives are divided into small sectors. The first sector is called the boot sector and contains the Master Boot Record (MBR).The MBR contains the information concerning the location of partitions on the drive and reading of the bootable operating system partition. During the bootup sequence on a <span style="font-weight: bold;">DOS-based PC</span>, the BIOS searches for certain system files, <em>IO.SYS</em> and <em>MS-DOS.SYS</em>. When those files have been located, the BIOS then searches for the first sector on that disk or drive and loads the needed Master Boot Record information into memory. The BIOS passes control to a program in the MBR which in turn loads IO.SYS. This latter file is responsible for loading the remainder of the operating system.<br /><br /><strong>What is a boot sector virus?</strong><br />A boot sector virus is one that infects the first sector, i.e. the boot sector, of a floppy disk or hard drive. Boot sector viruses can also infect the MBR. The first PC virus in the wild was Brain, a boot sector virus that exhibited stealth techniques to avoid detection. Brain also changed the volume label of the disk drive.<br /><br /><strong>How to avoid boot sector viruses.</strong><br />Commonly, infected floppies and subsequent boot sector infections result from "<span style="font-weight: bold;">shared</span>" diskettes and pirated software applications. It is relatively easy to avoid boot sector viruses. Most are spread when users inadvertently leave floppy disks in the drive - which happen to be infected with a boot sector virus. The next time they boot up their PC, the virus infects the local drive. Most systems allow users to change the boot sequence so that the system always attempts to boot first from the local hard drive <span style="font-style: italic;">(C:\) or CD-ROM</span> drive.<br /><br /><strong>Disinfecting boot sector viruses.</strong><br />Boot sector repair is best accomplished by the use of antivirus software. Because some boot sector viruses encrypt the MBR, improper removal can result in a drive that is inaccessible. However, if you are certain the virus has only affected the boot sector and is not an encrypting virus, the DOS SYS command can be used to restore the first sector. Additionally, the DOS LABEL command can be used to restore a damaged volume label and FDISK /MBR will replace the MBR. None of these methods is recommended, however. Antivirus software remains the best tool for cleanly and accuarately removing boot sector viruses with minimal threat to data and files.<br /><br /><strong>Creating a system disk.</strong><br />When disinfecting a boot sector virus, the system should always be booted from a known clean system disk. On a DOS-based PC, a bootable system disk can be created on a clean system running the exact same version of DOS as the infected PC. From a DOS prompt, type:<br /><span style="font-style: italic;">SYS C:\ A:\</span><br />and press enter. This will copy the system files from the local hard drive (C:\) to the floppy drive (A:\).<br />If the disk has not been formatted, the use of FORMAT /S will format the disk and transfer the necessary system files. On Windows 3.1x systems, the disk should be created as described above for DOS-based PC's. On Windows 95/98/NT systems, click Start Settings Control Panel Add/Remove Programs and choose the Startup Disk tab. Then click on "Create Disk". Windows 2000 users should insert the Windows 2000 CD-ROM into the CD-ROM drive, click Start Run and type the name of the drive followed by bootdisk\makeboot a: and then click OK. For example:<br /><span style="font-style: italic;">d:\bootdisk\makeboot a:</span><br />Follow the screen prompts to finish creating the bootable system disk. In all cases, after the creation of the bootable system disk, the disk should be write protected to avoid infection.Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com1tag:blogger.com,1999:blog-1417917570575260537.post-85902755335327879512007-02-10T15:56:00.000+05:302007-02-10T16:05:13.342+05:30What is a virus?In 1983, Fred Cohen coined the term “<strong>computer virus</strong>”, postulating a virus was "a program that can '<strong>infect</strong>' other programs by modifying them to include a possibly evolved copy of itself.” <strong>Mr. Cohen</strong> expanded his definition a year later in his 1984 paper, “A Computer Virus”, noting that “a virus can spread throughout a computer system or network using the authorizations of every user using it to infect their programs. Every program that gets infected may also act as a virus and thus the infection grows.”<br />Using that explanation, we can see that viruses infect program files. However, viruses can also infect certain types of data files, specifically those types of data files that support executable content, for example, files created in <strong>Microsoft Office</strong> programs that rely on macros. Compounding the definition difficulty, viruses also exist that demonstrate a similar ability to infect data files that don't typically support executable content - for example, <em>Adobe PDF files</em>, widely used for document sharing, and .<em>JPG image files</em>. However, in both cases, the respective virus has a dependency on an outside executable and thus neither virus can be considered more than a simple ‘<u>proof of concept’</u>. In other cases, the data files themselves may not be infectable, but can allow for the introduction of viral code. Specifically, vulnerabilities in certain products can allow data files to be manipulated in such a way that it will cause the host program to become unstable, after which malicious code can be introduced to the system. These examples are given simply to note that viruses no longer relegate themselves to simply infecting program files, as was the case when Mr. Cohen first defined the term. Thus, to simplify and modernize, it can be safely stated that a <strong>virus</strong> infects other files, whether program or data.<br />In contrast to viruses, computer worms are malicious programs that copy themselves from system to system, rather than infiltrating legitimate files. For example, a mass-mailing email worm is a worm that sends copies of itself via email. A network worm makes copies of itself throughout a network, an Internet worm sends copies of itself via vulnerable computers on the Internet, and so on.<br /><strong>Trojans</strong>, another form of malware, are generally agreed upon as doing something other than the user expected, with that “something” defined as malicious. Most often, Trojans are associated with remote access programs that perform illicit operations such as password-stealing or which allow compromised machines to be used for targeted denial of service attacks. One of the more basic forms of a denial of service (DoS) attack involves flooding a target system with so much data, traffic, or commands that it can no longer perform its core functions. When multiple machines are gathered together to launch such an attack, it is known as a distributed denial of service attack, or DDoS.<br />While purists draw a firm distinction between viruses, worms, and Trojans, others argue that it is merely a matter of semantics and give the virus moniker to all viruses, worms, and Trojans. The term malware, a.k.a. malicious software, can most easily be used to describe viruses, worms and Trojans while satisfying both arguments.<br />Malware is an even more appropriate term when one considers <a href="http://antivirus.about.com/cs/adwarespyware/">spyware, adware</a>, and and <a href="http://antivirus.about.com/cs/allabout/a/browjack.htm">browser hijacking</a> techniques that may not fit in any of the aforementioned virus, worm, or Trojan classifications. Thus, malware can be defined as any program, file, or code that performs malicious actions on the target system without the user’s express consent. This is in contrast to Sneakyware, which can best be described as any program, file, or code that the user agrees to run or install without realizing the full implications of that choice. One of the best examples of Sneakyware was <a href="http://antivirus.about.com/library/weekly/aa102402a.htm">Friendly Greetings</a>, a greeting-card trick that exploited users’ willingness to say Yes without reading the licensing agreement. By doing so, they were blindly agreeing to allow the same email to be sent to all contacts listed in their address book.<br /><br /><em>To recap:</em><br /><ul><li>Viruses infect other files;</li><li>Worms make copies of themselves;</li><li>Trojans perform malicious actions but do not spread;</li><li>Malware is an all-encompassing term that describes any malicious software program or file operating without the users explicit consent.</li></ul>Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com0tag:blogger.com,1999:blog-1417917570575260537.post-85303220430532339212007-02-04T14:03:00.000+05:302007-02-06T15:56:56.122+05:30Top 10 tweaks tips and tricks for windows vista<ul><li>If you’re annoyed by Internet Explorer’s incessant barking that you’ve lowered your security settings (like, if you’re a non-paranoid expert), launch “gpedit.msc” from either the Run command or Start Search field, navigate through Local Computer Policy / Computer Configuration / Administrative Templates / Windows Components / Internet Explorer. In the rightmost pane, double-click “Turn off the Security Settings Check feature” and set it to Enabled. </li><li>If Internet Explorer’s Information Bar also annoys you, you can turn it off (again) in the Group Policy Object Editor (gpedit.msc) through Local Computer Policy / Computer Configuration / Administrative Templates / Windows Components / Internet Explorer / Security Features. In the rightmost pane, double-click “Internet Explorer Processes” and set it to Disabled. Hallelujah!</li><li>I’ve just mentioned two tweaks that are buried inside the Group Policy Editor. <a href="http://windowsvistablog.com/blogs/windowsvista/archive/2006/12/15/multi-version-investments-using-group-policy-to-your-full-advantage.aspx">Jim Allchin pointed out</a> that there’s a <a href="http://www.microsoft.com/downloads/details.aspx?FamilyID=41dc179b-3328-4350-ade1-c0d9289f09ef&DisplayLang=en">Group Policy Settings Reference</a> spreadsheet available. Makes for great weekend reading. </li><li>Read the <a href="http://shellrevealed.com/blogs/shellblog/archive/2006/10/28/The-Background-on-Backgrounds.aspx">Background on Backgrounds</a> if you’re a performance junkie. Don’t set your wallpaper through Internet Explorer ever again! Now that Windows supports JPG wallpapers, there’s absolutely no need (or excuse) for using BMPs anymore. </li><li>If you insist on keeping UAC (User Account Control) turned on for yourself, you might care to make the elevation prompts a bit less visually jarring. <a href="http://www.brandonlive.com/">Brandon</a> told me about this one, even though I have UAC turned off. Launch the Local Security Policy manager (secpol.msc), and navigate through Security Settings / Local Policies / Security Options. In the rightmost pane, scroll to the bottom and double-click “User Account Control: Switch to the secure desktop when prompting for elevation.” Disable it, and you can keep UAC turned on without getting turned off by the embarrassingly craptacular <a href="http://shellrevealed.com/blogs/shellblog/archive/2006/10/12/Frequently-asked-questions-about-the-Aero-Basic-window-frame.aspx">Aero Basic</a> theme. </li><li>Vista can send you emails! The Computer Management tool can still be accessed by right-clicking “Computer” and selecting “Manage” from the menu. However, now you can attach a task to any event. Try navigating through System Tools / Event Viewer / Windows Logs / Application. Now, go ahead and select an event - then look to the rightmost pane and click “Attach Task to This Event.” Name it whatever, describe it however, click through the next step, then in the Action step, you’ll see the “Send an e-mail” option. </li><li>The Windows Task Manager gives you a lot more troubleshooting information in Vista. Flip to the Processes tab, and in the View menu, click “Select Columns” and add Description, Command Line, and Image Path Name. Moreover, when you right-click a process, you can select either “Go to Service(s)” or “Open File Location.” These are all long overdue options. </li><li>This one’s interesting. Open up the Date and Time Control Panel applet. Flip to the “Additional Clocks” tab. There, you can configure two more clocks from different time zones. They’ll appear in the tooltip when you hover over the Taskbar clock. No additional software (or silly sidebar widgets) necessary. </li><li>Applicable in other versions of Windows, I’m going to throw it in here for good measure. Create a shortcut to RegSvr32.exe in your SendTo folder. To get there quickly, enter “shell:sendto” in the Run command dialog or Start Search field. Now, when you wanna register a DLL or OCX file with the system, you can select it/them and “Send To” the RegSvr32 shortcut. </li><li>I figured I’d round out my first set of Windows Vista tips and tricks with a tiny bit of eye candy. It doesn’t beat Picasa, but the Windows Photo Gallery is better than nothing. Once it’s indexed all your photos, click the icon next to the Search field and turn on the “Table of Contents.” That’s kinda nifty. </li></ul><p>Thanks <a href="mailto:chris@pirillo.com">Chris</a> for <a href="http://chris.pirillo.com/2007/01/20/top-10-tweaks-tips-and-tricks-for-windows-vista">this great finding</a> on Windows Vista!</p>Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com0tag:blogger.com,1999:blog-1417917570575260537.post-34215539870563129202007-01-28T11:49:00.000+05:302007-01-30T09:24:07.158+05:30NEW VISTA FINALLYIn the span of five years, Microsoft promised its most advanced operating system ever and then yanked key features to meet deadlines that were missed anyway.<br /><br /><a href="http://www.flickr.com/photo_zoom.gne?id=371595818&size=o"><img style="FLOAT: left; MARGIN: 0px 10px 10px 0px; WIDTH: 200px; CURSOR: hand" alt="" src="http://img250.imageshack.us/img250/7406/tech2hv4.jpg" border="0" /></a>Yet Vista – due for launch January 30 – manages to largely overcome its long, tortured prelude. It includes improvements that take security, reliability and usability to new heights on the PC.Vista is by far the most robust and visually appealing version of Windows yet; although similar enough to its predecessor, Windows XP, to make the switch easy.That’s not to suggest Vista’s perfect. In more than a month of testing on multiple PCs, I’ve run into a number of rough patches. Then again, I was able to run my systems longer between restarts, experienced fewer crashes and generally found it more informative than its predecessor.<br /><br /><strong>But, is it good?</strong><br />Overall, yes, it is a worthy upgrade. Users, however, will probably want to wait until the kinks are worked out.<br />Be forewarned: The hardware requirements for the best features are high.Though a low-end version, Home Basic Edition, is offered, it lacks the high-end graphics and multimedia functions.Most consumers will likely want the Home Premium Edition that includes the visuals and entertainment tools and requires a heftier PC with at least a 1GHz processor and 1GB of memory.The visuals, for obvious reasons, are the most noticeable improvement, though the software doesn’t hesitate to downgrade the experience if your PC is too weak. Programs appear in semi-see-through frames that pop open and close with an animated swoosh. The flourishes aren’t just eye candy. They also help get the job done, particularly if you’re a multitasker.In previous Windows versions, minimised programs were something like a mystery: You knew they were there but it wasn’t easy to find anything. In Vista, live mini-previews of each window pop open when the cursor is moved along the task bar.<br />Switching between programs using the Alt-Tab key combination is easier, as the live previews appear there, too. A new combination – Tab-Windows keys – flips through all your programs like a 3-D stack of playing cards.The start menu has also been renovated. It now sports a search box that returns results instantly as you type.In fact, the improved search is fully integrated throughout Vista. Windows that display the contents of hard drive folders, for instance, all have a search box that can filter whatever is inside.Search results also can be saved into folders that get populated by future files that meet the original search criteria.By default, the right side of the screen is filled with small programs known as gadgets, displaying headlines, weather, microprocessor loads, memory utilisation – whatever. These default gadgets look great but aren’t terribly useful. The Really Simple Syndication gadget, which pulls headlines from news sites and blogs, only displays four items at a time.Hundreds of additional gadgets are available from Microsoft’s Web site. Some maintain the slick Vista visuals. Others don’t seem to try.<br /><br /><strong>Behind the scenes</strong><br /><a href="http://flickr.com/photo_zoom.gne?id=371595819&size=l"><img style="FLOAT: right; MARGIN: 0px 0px 10px 10px; WIDTH: 200px; CURSOR: hand" alt="" src="http://img411.imageshack.us/img411/1606/14429714vy8.jpg" border="0" /></a>Vista also includes considerable security improvements, including a firewall that blocks network traffic in both directions and an anti-spyware program. You still need to get your own anti-virus software. The operating system also has tools for monitoring and controlling your kids’ computer and Internet usage.<br />There are finer controls to adjust for power consumption and excellent notification and monitoring tools to figure out how the system is operating and what has gone wrong.<br /><br /><strong>Multimedia </strong><br />As for Multimedia, Vista’s capabilities include a photo management program with basic picture-editing capabilities and an improved upon XP’s moviemaking software, which also supports DVD burning. The premium editions also include Windows Media Center – a shell that makes playing music and video easy, even with a remote control. The program, previously part of a special version of XP, adds some of Vista’s visual pizazz to a package that bundles a digital video recorder for capturing live standard and high-definition TV.<br /><br /><strong>Installation</strong><br />How long does it take to give a PC running Windows XP this facelift? Surprisingly little, at least on a high-end PC with 2GB of memory: My installation took about an hour. After the software checked for updates, prompted me for a serial number and asked me to agree to the Windows user license, the installer ran without any need for input – an improvement over previous Windows versions. Problems arose when the PC came back to life. The beautiful visuals and inviting “Welcome Center” were covered up by error and warning messages detailing a number of incompatibilities. There was no sound. A program that I use to synch data with a flash-memory drive wouldn’t work. The Internet-phone software Skype couldn’t find audio input or output. And I was told the control centre for my ATI Radeon X1600 Pro graphics card “might” have an issue. There was no warning from Microsoft’s compatibility program that I ran before upgrading. Most of the problems were fixed by visiting each vendor’s Web site and downloading updated software, although I still couldn’t use my Hewlett-Packard LaserJet 1020 printer.<br /><br /><strong>In conclusion</strong><br />All said and done, the success of Vista won’t ride on how well old programs and peripherals will work but on the new capabilities that are enabled. For laptops, it may hinge on auxiliary displays that notify users of new e-mail when the machine is closed. For gaming rigs, it may be how well the games tap into Vista’s graphics capabilities. That’s because given all its bells and whistles, Vista is still just an operating system – a blank canvas, albeit one with a very pretty and elaborate frame.Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com0tag:blogger.com,1999:blog-1417917570575260537.post-35655110189904724542007-01-27T13:58:00.000+05:302007-01-30T09:17:18.786+05:3015 Reasons to SwitchWindows Vista is almost here. To anyone who has been sitting on the fence over whether to upgrade to Microsoft's new operating system, I'll say it loud and clear: It's time to make the jump. There are plenty of reasons to leave Windows XP and install Vista, and below are my top 15 favorites.<br /><br /><strong>It's the Interface, Stupid </strong><br /><br /><ul><li>Perhaps the best thing about Windows Vista is the most obvious: its new interface. With transparent animated windows that swoosh into place, subtle and elegant colors, a new Start menu, and plenty of other changes, this is the most beautiful version of Windows you've seen. If you've ever had Mac envy, this is the Windows you want--it's the most Mac-like interface yet.</li></ul><p><strong>Flip Over Windows Flip 3D</strong> </p><ul><li><a href="http://flickr.com/photo_zoom.gne?id=370517924&size=o"><img style="FLOAT: left; MARGIN: 0px 10px 10px 0px; WIDTH: 200px; CURSOR: hand" alt="" src="http://img453.imageshack.us/img453/4488/111pl5.jpg" border="0" /></a>Switching between open windows using Alt-Tab in previous versions of Windows was always a shot in the dark, as you never quite knew to which window you'd switch, or even which ones were open. That has all changed in Windows Vista. Press Alt-Tab, and Windows Flip 3D springs into action, displaying thumbnails of all your open windows in a gorgeous, 3D stack. You can then flip through them until you find the one you want. </li></ul><p><strong>Live Thumbnails</strong></p><ul><li>Do you run a lot of programs and visit a lot of Web sites simultaneously? If so, you'll appreciate Live Thumbnails. Hover your mouse over any window on the Taskbar, and a thumbnail of the window pops up, with the program and document name, or the Web site name, just above it. The thumbnails are truly "live," so if a video is playing in a window, you'll see the video playing in the thumbnail too. </li></ul><p><strong>Boost Performance With ReadyBoost</strong></p><ul><li>Windows Vista includes a quick way to enhance system performance: <a href="http://en.wikipedia.org/wiki/ReadyBoost" target="_blank">ReadyBoost</a>. It preloads files and programs you often use into RAM so that they're there when you want them, and you don't have to wait for them to load from the hard disk. You can buy an inexpensive USB flash drive and use up to 4GB of cheap RAM to boost your system performance.</li></ul><p><strong>Cool Performance Tools</strong></p><ul><li>If you're the kind of person who tends to peek under the hood and tinker, you'll find a lot to like in Windows Vista, which contains plenty of applets and utilities. Probably the best of them all is the Reliability and Performance Monitor. It keeps tabs on every aspect of your PC in exquisite detail, including the CPU, hard disk, network usage, and RAM use, and it includes plenty of charts, reports, and logs for your inner geek. The Reliability Monitor module is particularly noteworthy, as it charts the reliability of your PC over time and shows you every single problem or failure in a calendar format.</li></ul><p><strong>Better Security</strong></p><ul><li><a href="http://flickr.com/photo_zoom.gne?id=370517925&size=o"><img style="FLOAT: right; MARGIN: 0px 0px 10px 10px; WIDTH: 200px; CURSOR: hand" alt="" src="http://img444.imageshack.us/img444/7790/222ax2.jpg" border="0" /></a> At every level of Windows Vista, you'll find improved security. The firewall is now two-way, including inbound as well as outbound protection. <a href="http://www.microsoft.com/athome/security/spyware/software/default.mspx">Windows Defender</a> offers spyware protection, and Internet Explorer has an antiphishing filter to protect against Web scams. A slew of security holes have been plugged in Internet Explorer, and the browser now operates in what's called Protected Mode, which guards system files against external attacks. There's plenty more under the hood as well, including Windows Service Hardening, which protects vital files and settings. (Note: BitLocker's automatic drive encryption and other advanced Vista security options are available only in the Business and Ultimate versions.) </li></ul><p><strong>Find Anything Fast With Search</strong></p><ul><li>Can't remember where you put an important file? It's no longer a problem. Windows Vista integrates a new search technology throughout the operating system--on the Start menu, within Windows Explorer, and just about everywhere else you look. It uses indexing and is lightning fast, and it literally searches as you type. A powerful advanced search tool lets you narrow your search by date, file size, author, tags, and location. It also accepts Boolean searching. You can even save your searches for future reference.</li></ul><p><strong>Nifty Software Gadgets</strong></p><ul><li><a href="http://flickr.com/photo_zoom.gne?id=370517926&size=o"><img style="FLOAT: left; MARGIN: 0px 10px 10px 0px; WIDTH: 200px; CURSOR: hand" alt="" src="http://img258.imageshack.us/img258/2669/333uq4.jpg" border="0" /></a>If you're a software gadget fan, you'll love Vista. It includes a variety of <a href="http://softwaregadgets.gridspace.net">software gadgets</a> that live on the desktop and do little tasks such as delivering stock quotes, showing weather forecasts, displaying RSS feeds, monitoring the state of your computer, checking your e-mail inbox, and more. Vista ships with a gaggle of them, but you can find dozens more online-and they're all free.</li></ul><p></p><p><strong></strong></p><p><strong>Better Wireless Networking</strong></p><ul><li>Anyone who uses a wireless network at home, at work, or on the road will appreciate the way Windows Vista handles wireless networking. You can more easily find new wireless networks, and save them and manage them as permanent connections. Wireless security has also been improved: When you connect at a public hotspot, security precautions (such as the shutting off of file sharing) automatically lock into place.</li></ul><p><strong>Map Your Network</strong> </p><ul><li><a href="http://flickr.com/photo_zoom.gne?id=370517927&size=o"><img style="FLOAT: right; MARGIN: 0px 0px 10px 10px; WIDTH: 200px; CURSOR: hand" alt="" src="http://img258.imageshack.us/img258/5356/444cx9.jpg" border="0" /></a>Want to see every single computer and device connected to your network--and get instant information about each, such as their IP addresses? The Network Map does that for you. It also lets you make instant connections to any device; double-click a PC, for example, and you'll connect to its shared folders.</li></ul><p><strong>Better Graphics With Windows Photo Gallery</strong></p><ul><li><a href="http://flickr.com/photo_zoom.gne?id=370517929&size=o"><img style="FLOAT: left; MARGIN: 0px 10px 10px 0px; WIDTH: 200px; CURSOR: hand" alt="" src="http://img444.imageshack.us/img444/31/555kt0.jpg" border="0" /></a>Finally, with Windows Photo Gallery Microsoft has shipped a graphics utility that's worth using. It's a kind of jack-of-all-trades--you can view graphics and create slide shows, for example. But it also includes a surprisingly good set of simple-to-use image editing tools, including one for eliminating red-eye and another that cleans up photos with a single click.</li></ul><p></p><p></p><p><strong>Become a Director With Windows Movie Maker</strong></p><ul><li>Windows Vista comes with a new version of the much-maligned moviemaking tool Windows Movie Maker, and it's a big surprise--you'll actually want to use it. Importing video and music, creating transitions between scenes, and syncing music with video are easy. When you're done, you can burn your creation to DVD with Windows DVD Maker.</li></ul><p><strong>Better Notebook Support</strong></p><ul><li><a href="http://flickr.com/photo_zoom.gne?id=370517930&size=o"><img style="FLOAT: right; MARGIN: 0px 0px 10px 10px; WIDTH: 200px; CURSOR: hand" alt="" src="http://img409.imageshack.us/img409/7509/666tu5.jpg" border="0" /></a>In previous versions of Windows, the mobile-computing features seemed bolted on after the fact. That's not true with Windows Vista, as the Windows Mobility Center puts all the tools you need in one place.<br />You can turn your wireless adapter on or off, change your battery settings, and connect to an external display from a single location. And the new Presentation Settings feature is a big leap forward for anyone who often gives presentations with a notebook. You can customize settings--such as the resolution, mute, background, and so on-and then save them. Afterward you can switch from normal mode to presentation mode in a snap.</li></ul><p><strong>File Sharing and Syncing</strong></p><ul><li>With Windows XP it was possible to share files among PCs on your network--possible but often impossibly hard, it seemed. That changes with Windows Vista. The Network and Sharing Center lets you turn on and configure file sharing with single clicks. And the Synch Center lets you automatically synchronize files and folders among separate PCs. You won't have to do anything to keep them in sync; Windows Vista will do it for you. </li></ul><p><strong>Protect Your Kids With Parental Controls</strong></p><ul><li>Worried that your children may be exposed to inappropriate content online? Want to make sure they're not playing violent games? Parental Controls put you in the driver seat. Not only can you determine the kinds of sites they visit and games they play, but you can also enforce rules about when they'll be able to use the computer at all.</li></ul>Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com0tag:blogger.com,1999:blog-1417917570575260537.post-7900837479527650972007-01-23T20:36:00.000+05:302007-01-27T17:36:39.794+05:30PowerPoint 2003 Shortcut Keys<strong>Keys for General Use</strong><br />All shortcut keys are based on the U.S. keyboard layout. Keys on other layouts may not correspond exactly to the keys on a U.S. keyboard.<br />For keyboard shortcuts in which you press two or more keys together, the keys to press are separated by a plus sign, like this: <strong>SHIFT+F10</strong>.For shortcuts in which you press keys one after the other, the keys to press are separated by a comma, like this: <strong>ALT, F, X</strong>.<br /><br /><u>Working with Presentation Files</u><br />create a new presentation file : <strong>CTRL+N</strong><br />open a presentation file : <strong>CTRL+O</strong><br />close a presentation file : <strong>CTRL+W</strong><br />save a presentation file : <strong>CTRL+S</strong><br />quit PowerPoint : <strong>ALT+F4</strong><br /><strong></strong><br /><u>Keys for Displaying and Using Windows</u><br />when more than one window is open, switch to the next window : <strong>CTRL+F6 </strong><br />switch to the previous window : <strong>CTRL+SHIFT+F6 </strong><br />minimize a window to an icon : <strong>CTRL+F9 </strong><br />maximize a selected window : <strong>CTRL+F10 </strong><br />restore the size of the active window after you've minimized or maximized it : <strong>CTRL+F5 </strong><br /><strong></strong><br /><u>Keys for Moving between Panes</u><br />move clockwise among panes of Normal View : <strong>F6 </strong><br />move counterclockwise among panes of Normal View : <strong>SHIFT+F6 </strong><br />switch between Slides and Outline tabs of the Outline and Slides pane in Normal View : <strong>CTRL+SHIFT+TAB </strong><br /><strong></strong><br /><u>Keys for Sending a Presentation in an E-Mail</u><br />To send the current presentation as the body of an e-mail message, press <strong>ALT+F, D, C.<br /></strong>Use the following keys when the e-mail header is active. To activate the e-mail header, press <strong>SHIFT+TAB</strong> as many times as necessary. (If text within a text box is selected, you must first press <strong>F2</strong> to select the text box before pressing <strong>SHIFT+TAB</strong>.)<br /><br />select the next box in the e-mail header or the body of the message when the last box in the e-mail header is active : <strong>TAB<br /></strong>select the previous field or button in the e-mail header : <strong>SHIFT+TAB<br /></strong>open the Address Book : <strong>CTRL+SHIFT+B </strong><br />check the names on the To, Cc, and Bcc lines against the Address Book : <strong>ALT+K </strong><br />send the current presentation : <strong>ALT+S </strong><br /><strong></strong><br /><u>Keys for Showing and Hiding the Grid and Guides</u><br />show or hide the grid : <strong>SHIFT+F9</strong><br />show or hide guides : <strong>ALT+F9</strong><br />change grid or guide settings : <strong>CTRL+G</strong><br /><strong></strong><br /><u>Miscellaneous<br /></u>undo the last action : <strong>CTRL+Z</strong><br />repeat the last action : <strong>CTRL+Y</strong>Rupesh Pawarhttp://www.blogger.com/profile/01763847006582290806noreply@blogger.com3