Renegade programs can slip onto your system in an instant and they can be maddeningly difficult to banish. PC World's tests reveal the most powerful tools for fighting back.

Download.com offers this frequently updated guide to spyware control that contains relevant information and will allow you to download commercial anti-spyware programs as well as freely distributed ones.

The TopTenReviews.com research team has produced a side-by-side comparison of all leading commercial anti-spyware applications, including features, ability to detect and delete the different types of spyware and adware, and cost.

If you would like to extend your research beyond the above resources, this site is a good gateway. It contains a collection of links to spyware-related articles, reviews, and tech tips, and it highlights several free anti-spyware solutions.