I'm having the same problem - Vista Ultimate (32-bit), on a brand-new system (Core i7, DDR3 6GB, etc...). Get stuck at the "Scanning for ..." prompt.
I was able to use another pc with xp on it to upgrade to OS3, but can't use the VC on the new pc - it doesn't detect the virus.
I also noticed that in the Control Panel -->System --> Devices dialog that the Virus Midi controller won't start... not sure why though.
I've tried other usb cables, reset the virus multiple times, de/reinstalled drivers, etc... to no avail.
I too may try a pci usb controller just to see if that's the problem. I love my virus
and want to use it to max power with my new daw.