CPU usage at 100% constantly after waking from hibernation/sleep

Okay, I'm completely confused on this issue and I've baffled people at Dell,
which from experience isn't hard to do. I have a Dell Inspiron 1501 with
Vista Home Basic as the OS. My CPU usage bumps between 10% and 44% after I
first start up my computer. And when I allow my computer to sleep and then
wake it up, it runs at 100% constantly. I've tried stopping programs from
running in MSCONFIG, I've ran Ad-Aware 2007, Spyware, Registry Cleaner and
McAfee Virus scan. Nothing has corrected this problem and the programs have
cleaned off a few items, but still nothing has changed. I tried checking the
Reliability and Performance Monitor and I'm not educated enough in computers
to know what I'm looking at. Can someone please give me some ideas to
correct this problem? Dell thinks I should reinstall my OS and start over,
but I don't want to do this unless it's the last possible recourse.