Comodo Internet Security, VIPRE Antivirus, Norton 2009 and 2010 just to name a few. There are lots of other firewalls and Antivirus apps out there that work under 64 bit Win7. Google and ye shall receive.
windows security essentials, defender and Bullguard, am I using.
and a quick vipe of disk, if... got two compters, so have backup.
digitalvivo is absolutely right, think before you do something, and your computer might survive.
windows security essentials is actually very good, and can find them ALL.
Defender is rather useless.
Bylguard, well is an average virus-scanner.