Either your keyboard or your mouse connections are loose or you seem to have the same prob. that most people get when their mouse stops working. i would sugest you do a full scan for spyware and malware in safe mode. f8 at startup.
if it don't find nothing, then it's a driver issue...i would get ahold of a program called CC CLEANER
, and do a scan with that. this free program is very good at fixxing issues that can't be fixxed any other way.
you can find it here