I tried Adaware but found that it wasn't as effective as I thiought it could be. I then found that Optimum Online (Cable Internet Service) had a free Ad/Spyware (Spybot) and Pop-up blocker. So far I like Spybot better than Adaware. I'm working on getting the Pop-up blocker going soon. Link is here---->
http://www.optonline.net/popupstopper
When you select "Download Now" you'll have the option to download both above-mentioned apps.
I previously liked Earthlinks great Pop-up blocker but after it expired as a stand-alone application it was part of a larger browser suite. No thanks!
I've also found that spysweeper is an excellent preventative for Ads.....
http://www.spysweeper.com/