I too, have had a similar experience. With ONE excpetion, I have found that XP with SP2, combined with NAV and Ad-Aware and maybe Spybot S&D takes care of all spyware and viruses (of course, making sure that every product has all the latest updates), but I too had one PC where, no matter what I tried, the spyware (or whatever it was) could not be eliminated.

Thanks for the info.

Check out some of my favorite tools:
http://www.answersthatwork.com/
http://www.ghisler.com/
(Total Commander)
http://www.winguides.com/tweak/
(Tweak manager)
http://www.ccleaner.com/