If you need to scan for virus or worms do the following free scans
www.trendmicro.com/hc_intro/default.asp
www.bitdefender.com/scan8/ie.html
www.kaspersky.com/remoteviruschk.html
www.ewido.net/en/onlinescan/
All of these scanns are excellent
A virus worm or trojan can kill your PC in a few days
all of the simple need is to scan and keep it free of these malicious things.
Its time consuming to scan but well worth it to do simple and easy read follow the directions and scan.