Try resetting bios to default. Is usb enabled in bios?
If you can browse the bios with the keyboard, recovery console should also work....
And I think your best bet would be the Recovery Console (set Cd to boot first from bios ,press r when Win CD loads)
You could try a manual restore point within System restore at the cmd ( a bit tricky, see here: http://forums.whatthetech.com/index.php?showtopic=105819),
or try replacing files from the Windows\Repair to System32\Config.....(make backup copies of what you're replacing)
It could also be a chipset driver problem for some models.
See also here, something similar, when uninstall nvidia drivers: http://forums.nvidia.com/index.php?showtopic=83267