http://www.free-av.com/.
Normally i dont really like to post free virus scanners. they always are miles haead with updates on the payed virusscanners, and your not always sure what you dl.
However, as a on regular bass pc magazins reader i found this article that compared paid and free virus scanners. This virus scanner aint the best, but in the top 3 of overall it scored the third place.
So if your lookin for a free virus scanner, you might want to consider AntiVir Personal Edition

http://www.hbedv.com/download/download.htm also looks intresting