This is a free virus scanner, comes highly recommended by the staff at Tech-TV;
http://www.grisoft.com/html/us_index.htm?
session=e8e6087a9476b943be27fb252c34781c
(I know, superlong url)
Good luck,
BB-NYC Member # 4105 ('89, black, 66,000 mi. K&N drop-in, ShoShop billet 
flywheel, alum SFB's Josh T Ceramic TOB and reinforced mounts)