You know what, I would think it's an overheating problem. I've gotten a lot
of responses like that, and its logical. When I touch the bottom of my
computer the heat (in my estimation) is a little below the threshold of pain.
(Sometime I should try to get the exact temperature).

But here's why I don't think it's (just) the heat. A while ago, I
reformatted and tried the games with nothing else on my computer (except what
was preinstalled which excludes SP2 and Office), and there were no slowdowns
at all. So I'm wondering if there's a driver or some software that is making
my CPU work harder. . . But as I said, I have no spyware or viruses causing
it.