. . with AVG - preferably the paid version (I'm registered as a dealer with them). The current version 8.0 has one of the top anti-spyware programs fully integrated. Many of the worst infected machines I see are running Norton so I definitely don't recommend that - it's sole purpose seems to be to slow the machine down and make clean-up difficult (it identifies most of the tools I use as dangerous viruses and tries to remove them).