Aye, I've never heard of a virus attacking the USB. It may have corrupted the drivers a bit in an attempt to, but unlikely. Install service pack 2 if you want your network to give you wierd inexplicable problems, but it does fix alot of other stuff. I would suggest re-installing your usb drivers and maybe your chipset drivers too, I had a problem with my USB and I had to install different chipset drivers to avoid bluescreening anytime I plugged/unplugged anything.