One other thing you should do, in Internet Explorer >Tools> Internet Options > Privacy, move the selector all the way up so the site can't upload their cookies to your computer (before you surf the net).  Of course, slide it down again when you want to enter trusted sites like Renderosity.

Every day go into IE Tools >Internet Options, select delete and delete files and delete history, then go to settings, open it and delete all those cookies that you failed to stop (Except of course for Renderosity and your other trusted sites).  Then go to Disk Clean up or your other favorite scrubber and clean the rest of the trash off your hard drive (one can accumulate 30 plus megbits of the garbage everyday--you can intercept a lot of spyware there) .   Jan