Lavasoft Ad-Aware Free is a Free Antispyware Software for Windows by Publisher Lavasoft Ltd.
Ad Aware Free http://www.ereviewguide.com/media/reviews/photos/thumbnail/260x200c/56/93/10/_lavasoftadawarefree_1325565339.png
Average user rating from: 1 user(s)
You can't beat this for the price
I've been using the free version of Ad Aware for years. It won't catch everything because I have had a few things slip through, but it catches most of the ad and spyware that tries to get lodged on my system. The best part is that it doesn't slow my system down perceptibly so I can continue to work while it's scanning. Very few of these type of programs can do that. I'm frankly shocked that they don't charge for it.