Programs using too much CPU.

Sorry if this is in the wrong section. My the programs on my computer have been using up a lot more CPU then then normally do. I have tried several malware scans, and they all failed to find anything. I have tried defragging but it hasn't helped my situation. I'm not very good with computers, so I can't think of anything else that would cause this.

 

Right now firefox.exe, Enso.exe, services.exe, xfire.exe, csrss.exe and ctfmon.exe are using the most CPU. When I'm idle, there's usually about 3-5 programs that are using about 1-3 CPU. The programs and how much CPU they're using is constantly changing.


As for system idle, it usually stays around 90%+ and occasionally gos below 90%.

 

When I'm idle, my CPU usage tends to stay around 1-5%.

Here's the task manager when I'm not doing anything.
http://i218.photobucket.com/albums/cc72/bacnnn/cpuissue2.jpg

This is what it generally looks like when I try to play anything. The game I'm playing is using the same engine as Quake 2. A few months ago it never used more then 3 CPU.
http://i218.photobucket.com/albums/cc72/bacnnn/cpuissue.jpg

My computer just runs slower whenever I try to run anything.

I'm running Windows XP Professional x64 Edition.

Right now, I have AVG and Spybot installed.