Avast Anti-Virus- A wonderful free anti-virus program with several features including a pre-boot scan. Be sure to register your free copy. Avast is easy to use with automatic updates.

AVG Anti-Virus Free Edition 7.5 -AVG Anti-Virus Free Edition is the most popular free solution available at no cost to home users and provides the high level of detection capability that millions of users around the world trust to protect their computers.

TC-Spy - TC spy will protect you by scanning your entire computer system against a database of thousands of known spyware and adware threats and then alert you to any infections found. It will also provide you with a detailed report and clean any infections found.
Adaware 2007 - With the ability to scan your RAM, Registry, hard drives, and external storage devices for known data-mining, advertising, and tracking components, Ad-Aware 2007 easily can clean your system, allowing you to maintain a higher degree of privacy while you surf the Web.
ATF Cleaner - The main screen allows the user to either clean all temporary files, or select files for cleaning. The program also knows if Firefox and or Opera is being used, and gives the option of cleaning the temporary files associated with those applications
Mailwasher Anti Spam Software - The reliable spam blocker, protect your computer from unwanted email spam and stop viruses before you download them.
Mozilla Firefox - The award-winning Web browser from Mozilla is now faster, even more secure, and totally customizable to your online life.