Step 1: Antivirus software
Avast --My personal preference
Avira --Make sure you pick the right site (I just download it from download.com), some say that it is annoying.
AVG --Nice quality, but once again, my personal preference is for Avast
... and I don't know why they all start with av
Another program that should be installed alongside almost any anti-virus program is ThreatFire. This program analyzes program activity, rather than virus signatures, to detect viruses, so it performs magnificently against new threats that haven't been seen by your anti-virus company yet..