Spybot - Search & Destroy (often Spybot-S&D) can detect and remove spyware of different kinds from your computer. Spyware is a relatively new kind of threat that common anti-virus applications do not yet cover.
SpywareBlaster can help keep your system spyware-free and secure, without interfering with the "good side" of the web. And unlike other programs, SpywareBlaster does not have to remain running in the background.
avast! Home Edition is a complete ICSA certified and Secure Computing Magazine awarded antivirus software for home noncommercial use. This antivirus freeware has Anti-spyware built-in, Anti-rootkit built-in, and Strong Self-protection.