Do an on-line scan here..
http://housecall.trendmicro.com/hous...start_corp.asp
Get Spybot ..run that...
http://www.safer-networking.org/en/index.html
Get Adaware too... and run it..
www.lavasoftusa.com/software/adaware/
Um..lets see what else..ah yes.. on-line Trojan Scan ....
http://www.windowsecurity.com/trojanscan/
Make a new folder in your bookmarks/favourites and call it 'Security'.. place all those web sites in that folder and you'll never lose them
Be carefull what you download and where you go on the net. One other bit of advice, get the Firefox browser and install it.. you can stop the popups which sometimes can cause problems. And scan all files (maybe not mp3s) you get with your anti-virus before you do anything at all.
Good Luck