How to Clean Up a Windows Spyware Infestation by Coding Horror
Coding Horror has published a great, detailed post on how to clean spyware off of your machine if it ever gets infested.
http://www.codinghorror.com/blog/archives/000888.html
The directions he outlines are probably a little overwhelming for the average computer user at home. For average computer users that I know, when they ask about protecting against adware/spyware, I usually point them to Ad-Aware and Spybot. Installing and running those on a regular basis should keep adware/spyware at bay.
