Anti-Spyware
Spybot: Search & Destroy: Spybot is one of the best anti-spyware programs. Not only does it detect and attempt to repair the vast majority of spyware, it can also help to immunize your computer from future issues. For non-commercial use only. Commercial users need to purchase a license directly from Spybot.
Windows Defender: If you have Genuine copy of Windows XP, you can download and use Windows Defender. Windows Defender also removes the vast majority of spyware, and like most anti-virus programs, does a periodic scan to ensure your computer stays fairly clean. If you have Windows Vista, you already have it installed, so we advise you ensure it stays up-to-date and make sure it's set to do regular scans.