Okay, pretty soon windows 7 will be out I hope it will be better than Vista, but I will not let go of XP as yet. Its very stable and a lot of apps are compatible and so are a lot of games. Really I find no reason to upgrade to higher “glossier” versions when I can apply themes to do that by my self. Anyway, in this post I include applications that I find really helpful and which are freely available. Hope you find them useful too
1. Web Browser

The first place to start is to get a good browser. I personally prefer Firefox as it is fast and has many many useful add-ons. You can download it for free here. There are thousands of ways to customize your browser and the cool add-ons will help you do that. You can download add-ons here. Apart from Firefox, there is Google’s Chrome which is very sleek and fast and available for free download here. Though there not many add-ons, you can expect them in the near future. Opera is also a very good browser that can be downloaded for free here.
2. Antivirus

This is the most essential thing for your computer. Personally i recommend Avira Antivir which is free and has a very good and provides excellent protection from virus, worms, trojans, backdoor programs, etc. Regular updates will keep your system protected from the threats. Download it here
AVG Anti-virus Free Edition would be my next recommendation. Although I have personally found Avira to perform better than AVG, but still AVG also is very good compared to other solutions on the net. Free download from here
3. Text editor

Of course there is notepad to edit your text, but I find it not up to the par. notepad++ is not just text editor, it can be used for syntax highlight for C, C++, Java, HTML, XML, VHDL, pascal, pearl, lisp, CSS, ADA, Python, MATLAB, Verilog and many more. It has tabbed view allowing to open multiple documents in the same window and also has multi-language support, drag and drop and macro recording and playbacking. It can be downloaded for free from here
4. Media Player

Time to watch movies. Ideally, VideoLAN VLC media player is the one that can play almost all the formats. I recommend you download it from here. It can also be used as a media converter or a server to stream in unicast or multicast in IPv4 or IPv6 on networks. Basically you can listen to internet radio using this and view podcasts from various streaming sites.

Another very powerful tool is Media Player Classic along with its CODEC pack. Download the K-lite codec pack from here which of course is free. While installing it select the options “lots of stuff with player” to install all the CODECs and Media Player Classic. This will be able to play 99% of the movies available online including flash, .mkv (MP4 or H264) and many more. The same site lists a lot of CODECs that can be used in case you come across any format not supported by MPC.
5. MP3 Player

Although the above mentioned media players can play all the audio formats, I use winamp to play my MP3 songs. I find winamp to be the best in terms of handling my media library and creating playlists. It also has auto-generated playlists that I find really useful. Its interface is also very user friendly and it has a lot of skins which can be downloded from their website. download winamp here. Choose the free version which includes all the features that you will ever require
6. File and folder compression

7-zip is your best choice for compressing files and folder. It supports unpacking of ARJ, CAB, CHM, CPIO, DEB, DMG, HFS, ISO, LZH, LZMA, MSI, NSIS, RAR, RPM, UDF, WIM, XAR and Z formats and can compress your files and folders to 7z, ZIP, GZIP, BZIP2 and TAR format. This free app can be downloaded here

To compress your files and folder to RAR format, you can use winRAR. This is not a free application and hence you will need to buy it. winRAR also is very powerful and supports almost all the formats mentioned above. Even though it is not free, still it can be used along with the minor inconvenience of a pop up screen every time you run it. You can get winRAR here
7. Download Manager

This will let you download at higher speeds than your browser and will help you organize your downloads properly. Orbit download manager is a free app that will let you download streams from popular site such as youtube and also has pause and resume option. This is a stand alone app that can be found here
Firefox users can get an extension called Downthemall from here which will pretty much do the same thing as orbit.
8. CCleaner

CCleaner is a free system optimization, privacy and cleaning tool. It removes unused files from your system – allowing Windows to run faster and freeing up valuable hard disk space. It also cleans traces of your online activities such as your Internet history. Additionally it contains a fully featured registry cleaner. Download it from here.
9. PDF reader

Apart from the adobe reader, you can use Foxit PDF reader. Foxit Reader is a free PDF document viewer, with incredible small size, breezing-fast launch speed and rich feature set. Foxit Reader allows you to draw graphics, highlight text, type text and make notes on a PDF document and then print out or save the annotated document. Download the free version here.
10. Torrent client

For all your movies, games, apps, songs downloads use torrents. µTorrent is the world’s most popular BitTorrent client. Most of the features present in other BitTorrent clients are present in µTorrent, including bandwidth prioritization, scheduling, RSS auto-downloading and Mainline DHT (compatible with BitComet). Additionally, µTorrent supports the Protocol Encryption joint specification (compatible with Azureus 2.4.0.0 and above, BitComet 0.63 and above) and peer exchange. Schedule and queue your downloads or limit their speed so that you can browse while they download. Download it for free from here. There are many popular torrent sites such as isohunt.com or thepiratebay.com where you can search for torrents
11. Search engines

Google desktop search is a free app from google that allows you to search for any file on your system. Not only file names, but also the content itself. Very useful and much better and much FASTER than the windows search. It also comes with a side bar which I dont like much. Anyway, you can use it if you like or disable it. Download it from here
Launchy is a very useful lite app that basically searches your program menu. Highly useful to launch any application quickly from the cluttered programs menu. Get it for free here. Use the .exe file for windows XP.
12. image editor

Picasa is a free and powerful app to edit and manage your images and share them on the web. It lets you manage all your photos from a single place and allows you to eliminate scratches & blemishes, fix red-eye, crop and more. Turn photos into movies, collages, slideshows and more and share them by uploading them on the web with the picasa web albums. Download picasa from here
13. Dictionary

WordWeb is a one-click English thesaurus and dictionary for Windows that can look up words in almost ANY program. It works off-line, but can also look up words in web references such as the Wikipedia encyclopedia. A really helpful and must have app. Get the free version here
Note: Please comment for any help and suggestion. Please report any broken links and it will be fixed