I use
Spy Sweeper,
Symantec Anti-Virus, and a free download of
Spybot Search & Destroy.
I just have regular old Spy Sweeper, none of the anti-virus that can be bought with it. That is the one I use regularly to sweep my computer. Once a month (if that even) I'll run Spybot and Symantec. Several months ago I was having a ton of crap showing up on my sweeps and I tweaked a few thing on my 'net options and rarely now do I ever have anything show on my sweeps.
It doesn't pay to run through the internet bare-naked.
