This question already has an answer here:
For some reason, the Generic USB Keyboard driver was removed, literally, over night, from Windows.
Can someone that has Windows 7 and uses a USB Keyboard without any fancy drivers (i.e. uses Generic Windows USB Keyboard driver) go to
Device Manager>Keyboards>USB Keyboard>Properties>Driver>Driver Details
and post the name of the driver system files (for example "C:\Windows\system32\DRIVER\i8042prt.sys")?