Ubuntu Linux - The best Linux distro I have come across. I have not yet switched over to Linux. Ubuntu is my first choice if and when I decide to make a switch. However installing a multiboot system is a pain, particularly so if you have a combination of SATA and PATA drives. You will need tools like SBM. Leave it to geeks!

OpenOffice.org - The best replacement for MS-Office. It has everything you need. You can export documents to pdf format. It may not have some exotic and never used 'features' of MS-Office.

Mozilla Firefox - Most secure web browser. It is only next best to Opera. I prefer Firefox to Opera because of many extensions I can't live without.

Mozilla Thunderbird - A very nice email client.

7-zip - Open source archiving utility offering better compression ratio than its commercial counterpart. It has all the features you will ever need and supports all popular formats.

Filezilla - Fast and free full fledged FTP client. You will need it if you maintain your own website. For small uploads I use a Firefox extension Fire-FTP.

AutoHotKey - It is an Open source utility for windows. It is used for... hmmm... everything. Better visit the site to know more.

Free Software

Zone Alarm Free - Freeware version of popular personal firewall. It is sufficient for most home users. Commercial versions with more features are available.

AVG Antiirus Free - Free version of antivirus software by grisoft. Free for non commercial use. There are several other free antivirus software available for non commercial home users, Avast! and Avira Anti-Vir for example. I have chosen AVG for its performance and frequent updates.

Spybot Search & Destroy - Adware / spyware detection and removal software adjudged as the best privacy protection tool.

Wordweb free edition - English dictionary and thesaurus. Sits in your system tray allowing you to check any highlighed word in any window.

Autopatcher - An incredibly useful software, best described by it's authors -

"How often do you install Windows? Crashes, viruses, or even fixing other peoples' computers... Most people install their operating system regularly, whether they want to or not. After a while, you will get sick of going to Windows Update and continuously downloading patch after patch, update after update. Well, we have just the thing.

AutoPatcher is a comprehensive collection of patches, addons and registry tweaks that give you peace of mind in the knowledge that your Windows system is up to date, even before you connect it to the Internet. It's designed to quickly patch a system with the most current updates and tweaks available, and requires no user interaction once you have selected what to install."

Update: Unfortunately Microsoft has issued a cease and desist notice to the site owners. The download page has been taken out.

Update2: Autopatcher team has come up with a solution to download patches directly from Microsoft servers and build Autopatcher locally. Visit the site for details.