High CPU usage

High everyone, some help please.

I'm new so bare with me.

I'm having huge issues with CPU usage.

It is the worst when I try playing Madden 08

This has only started happening two days ago.

I have not installed anything new in this time.

I've already tried the whole svchost.exe thing and while it is running abnormally high it does not seem to be the main issue since what ever I'm using at the time has the highest usage.
everything is running too high
like right now firefox is using 128,060k
and the next highest is Microsoft windows search indexer which is at 26,250k

Any ideas what the problem could be?

let me know if I need to give any information.