Keyboard Problem

Hello,
I've got a Microsoft Wireless Keyboard 6000 v3.0 and I can't type a capital c or x or a question mark, but lower case is just fine. I think this might be a software problem, so is there any way to remove the driver/kext and reinstall it to make it function again? If I'm totally wrong please tell me!
Thanks for your help

By the way button mashing it for a while sometimes fixes it, but it's not the greatest solution.

 

Anybody Know?