For those who don't like to make there computer damn slow by installing anti virus programs, there are online virus scanning tools that is very efficient in detecting and removing virus and other spy wares. Most of the online virus scanning tool are Free and so most of them don't do the complete removal of virus. Some of the most effective online free virus scanning tool are listed below.
Trend Micro™ HouseCall
Symantec Security Check
BitDefender Free Online Virus Scan
Free Virus Scan - Kaspersky Lab
Windows Live OneCare
Note: All scanning tools will run only in windows explorer.