Every once in a while, when I'm surfing the web, a new window will open up on it's own, going to various websites and search pages. Stuff like http://messagebroadcaster.net/bannerfarm/link/800p/tt.htm and http://www.computercashcow.com/money. I've run AdAware and Spybot, they removed some things, but this stuff is still happening and it's frustrating. What should I do?