Win98 computer spontaneously shuts down!

Of course, I first checked Power Management in Control Panel — everything was set correctly to keep monitor & HD on all the time.

Then, on someone’s advice, I checked to see if I could disable Power Management in BIOS — but it was already disabled. So I changed to “user enabled” thinking that it would defer to control panel settings. That didn’t work either.

Are there any other settings I can check/change to stop this from happening? (My boss’ computer…:( )

Thanks in advance,
Sherry