Reinstalling USB devices without a kb and mouse

So my friend was having issues with his computer. When he plugged in a USB hard drive it would not operate. Reading the internet he decided the solution was to remove his USB drivers and let windows 7 reinstall them on the next reboot. Unfortunately windows did not reinstall them on the next reboot. Now all his usb devices including kb and mouse no longer work and the computer has no PS2 ports. What to do?

Edit: fyi the kb and mouse still work in bios and in safe mode until you log in, at which point they stop working

If you boot from CD and chose repair, anything you can do there?
Otherwise you could try other input devices, see if they install.

What's the model of board and current BIOS revision, and has he tried different USB ports?

I don't know about the board and BIOS (a 1 year old dell XPS something), but it is obviously a windows issue as the kb and mouse still work in BIOS. He has tried all the usb ports and multiple mice and keyboards. They all work in all ports in BIOS and work until he logs into windows. Don't have a repair disk but i guess I need to figure out how to get him one.