Buzz,
Also try this. Check out your start-up and resident programs and services by selecting Run from your Start menu. Type in MSCONFIG.
If you have Vista I think you have to type it in the Search box.
A System Configuration Menu should pop up. From there you can disable or enable start-up programs and services (though be very careful what you turn off). If your computer crashes just restart without saving any changes. Here is a good site that can help you out with this:
How to use MSCONFIG
Also here is another good site I have personally used to optimize my XP and make it run faster:
Optimze XP
For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.Dr. Carl Sagan