Follow the link provided and downloaded the software from the page.
Browser
Mozilla Firefox: It is considered to be the best browser available and is most widely used browser after Microsoft's Internet explorer.
Google Chrome: It has been recognized as the fastest browser and it is the third most widely used browser.
Audio and Video
VLC Player: A highly portable open source multimedia player capable of playing most of the audio and video file formats.
Miro Video Player: It is a free and open source HD video player. It can play almost any video file and offers over 6000 internet shows and video podcast.
Media Player Classic: A very light weight and simple video player for windows.
Audacity: It's a free audio editor for recording, Slicing and mixing audio files.
Office Suites
Abiword: An open source word processing program.
Openoffice.org: A completely free and open-source office program, you can use this program to do all your MS Office work.
PDFforge: A free software to help you create PDF projects.
Scribus: It's a professional layout and publishing software.
File Sharing
Cabos: A great software for firewall to firewall file transfer.
DC++: An open source Peer-to-peer file sharing client.
Shareaza: A peer-to-peer file sharing program for windows.
Ares: It's a P2P file sharing program which allows you to share Music, Software, reviews and much more.
Frostwire: It's a totally free limewire alternative and you can use it for free P2P file sharing for Gnutella and BitTorrent protocols.
CD/DVD Tools
Handbrake: Free and open source DVD ripper/Converter.
InfraRecorder: A free CD/DVD burning software.
Image/Graphics Tools
GIMP: An open source Image manipulation program for windows.
Inkscape: A Vector graphics editor, similar to adobe illustrator.
Blender: An open source cross platform suite of tools for 3D creation.
Paint.net:(not open source) A free image editing software for windows.
Dia: It is a drawing software that helps you draw structured diagrams.
FTP/SFTP
FileZilla: An open source FTP client for Windows.
WinScp: A free SFTP, FTP and SCP client for windows.
Instant Messaging / IM
Pidgin: A very popular chat client, which helps you connect MSN, Google Talk, Yahoo, AIM and other chat networks at once.
Miranda IM: A portable and multiprotocol instant messaging application for windows.
Email Clients
Mozilla Thunderbird: A popular and a great alternate to Microsoft outlook. It has intelligent spam filter which filters all the trash emails and has an inbuilt RSS reader to read all you feeds at one place.
Claws Mail: An open source GTK+ based email client.
RSS Reader Software
RSSowl: A powerful application to organize, search and read all your feed at one place with a ease.
RSSbandit: Helps you read news feeds and download podcasts from your desktop only.
Security Tools
Passwordsafe: A free software to help you manage you passwords safely.
TrueCrypt: An open source disk encryption software for windows.
Eraser: A secure data removal tool for windows.
ClamWin: A very popular open-source antivirus to scan your PC for virus and also get free virus updates.
Utilities
7-Zip: A file achiver which supports ZIP, GZIP, BZIP2 and Tar format.
CobianBackup: A very useful backup software for windows.
DR Freeware: A great software which helps you in recovering your lost data, mail recovery, drive backup, data undelete, password reset for windows.
UltraVNC: A powerful software that helps you connect to another desktop through remote desktop connection.
PeaZip: It's a free and open-source file archive manager which helps you extract, compress, encrypt and secure deletion.
Web Related / Developers
Notepad++: A free text editor and source code editor for windows.
DotNetNuke: It's an open source platform for building website based on Microsoft .Net framework.
Xampp: A simple Apace distribution containing MySQL, PHP and Perl.
Firebird: A free database management system for windows.
PHPMyadmin: An application to handle the administration of MySQL.
BookmarkSync: It's a bookmarking service which allows you to access your favorite bookmarks from any computer and any browser.
WebDevloper Suite: A windows based platform for development, testing and deployment of PHP and MySQL websites and application.
Curl-loader: A simple software performance testing tool written in C language.
NVU: An alternate to Dreamweaver software.