Anti-Virus 

Symantec
Norton AntiVirus 2007 blocks viruses and spyware with advanced protection.  This latest version delivers even greater security to protect users against the current landscape of evolving and increasingly dangerous risks.  Norton AntiVirus’ proven detection and removal capabilities can protect against infections from ever installing on users’ computers.  Norton AntiVirus now provides zero-hour protection by blocking attacks from entire categories of worms and viruses without requiring unique signatures for each new threat.  Norton AntiVirus 2007 also includes enhanced capabilities for finding and removing hidden rootkits running on the system that may be controlling the user’s computer. 

McAfee
McAfee's award-winning anti-virus protection automatically protects your PC, email and downloads against virus, worms and spyware.

AVG
AVG Anti-Virus 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.

Spyware

Adware

Free Open Source Software