http://support.microsoft.com/kb/331796
It's a basic step the EA support guys will ask you to try if you call them.
Punkbuster shouldn't. I would recommend trying to update it manually if you haven't done so already.
http://www.evenbalance.com/index.php?page=support-bf3.php
What do you mean by keys btw?
Lee- yeah, looks like they came up early and I'm stuck in work :<
Read somewhere you could press some keys and some monitoring stuff GPU temp etc would come up on screen during game. Maybe I read it wrong

