Three tools to keep clean these days.
Computer Associates online virus scanner
CWShredder
Spybot
When your computer is clean and your W.i.n.d.o.w.s.XX is updated (all criticals), you
don't need software firewalls and virus checkers. VCs and FWs slow down your
computer and if you don't click on email attachments and scan pirate software
before you click on it then you don't get infected.