Bios virus or Bad MoBo?

MoBo:Nvidia 650i Ultra Ram:2gigs DDR2 None of the usb’s (2 back 2 front all 4 plugged into MoBo correctly) work. Plugged in my old ps2 connection mouse and booted up, worked fine. Went to device manager and the usb’s weren’t even listed. I downloaded the drivers from Nvidia.com and when I was about to install it(63.54 mb size and I had 200+ free gigs of space) it told me there isn’t enough space. ran AVG 8.5 (full version), Norton, and Mcafee, all three came up with nothing. I thought It could be the integrated USB’s went bad, but the simple plug in usb’s in the front are not showing up as well. Should I back data up and format/reinstall windows? Is there a way to remove nasty bios viruses?