>> How much RAM memory? What is the Total, the Commit Charge and the Peak?

Total: 512M
Commit Charge: 187M
Peak: 1.2G

>> How large is your hard drive?

Total: 40G total
Free: 11G free
Format: NTFS, 1 partition

I downloaded the program you recommeded and it's telling me some
interesting things: the missing CPU time is being used by hardware
interrupts. Since I've never used this program before, I have no basis
for comparison but that seems rather high. I'm going to run it on an
identical machine down the hall as soon as it's owner leaves it
unguarded. That should give me a clue.

Thanks for the link to Major Geeks - I'd forgotten all about them. I've
been using the WinTasks Process Library at
http://www.processlibrary.com/, which I think is pretty good, too.