Keyboard disabling inputs? (troubleshooting)

[FrozenLava]

i was working on a friends computer, and when I plugged my cables back into my computer and booted up... well, neither my keyboard or mouse works at the log on to windows promt (XP pro). keyboard works in the bios, as well as to select safe mode.

The mouse moves until i strike any key on the keyboard, which seems to disable the mouse as well.

I tried a different keyboard with the same results. Any ideas?

edit: it also acts the same in safe mode