I previously wrote about Lavasoft Ad-Aware, which is an excellent spyware software. In that article I also mentioned that I I addition use Spybot to complement Ad-Aware on the Spyware prevention side.
Spybot - Search & Destroy can detect and remove a multitude of adware files and modules from your computer. Spybot also can clean program and Web-usage tracks from your system, which is especially useful if you share your computer.
I have used Spybot for a number of years and highly recommend this to be installed on any Windows PC's to ensure that your PC stay free of spyware.
Don't forget to update, immunize, and run a spyware check at least once a Month !!
An external review + download url can be found on: http://tinyurl.com/6rmh4b
The Spybot website can be found on: http://tinyurl.com/2c4c69