When I had to take my PC in last year (december 2004) because it was having problems, the computer store said it was all the spyware and viruses. We had to reformat the hard drive--what a pain. The store recommended AVG for viruses and Spy Sweeper for spyware. I use both of those plus the Lavasoft and Microsoft spyware proggies. So far (knock on wood), we've had a year free of problems. Since my IPS is SWB Yahoo!, we have their free pop-up blocker and spyware proggies, too.