How many processes total are running? The CPU usage seems a bit high. I don't use Outlook, but I opened it and have firefox open and I only hit 8% CPU and that was only for a split sec. I sit at 0-4%. If your numbers are constantly running in the teens and twenties, you have something going on.
Get Hijackthis -
http://www.majorgeeks.com/download5554.html and run a scan only, save the info and post it.
Dave