download McAfee Stinger, it will scan for the main viruses, such as ones that get sient via msn, that 9 times out of 10 do not actually come from anyone you know....you get spammed a message or picture from somewhere, thats tricks you into thinking it's from someone you know.
http://vil.nai.com/vil/stinger/
follow the instructions for your particular operating system, as you
must disable system restore, otherwise the virus will still remain.