This is something I have learnt when it comes to viruses...
Get a live cd/dvd/usb of a linux distro and then install clamAV and scan your drive from that. This way you can scan ur drive as if you had taken it out and put it as secondary hard drive in another pc. Thus giving you a good deep scan Linux Mint/Ubuntu are easy distros to d/l and easy to insatll clamAV on after a quick google