wrote
snip
For the original poster, start by checking that all of the fans are
still working. In particular the CPU fan. It's more likely that
you've got a bad fan than a bad power supply.

The fan works fine, thanks.

Sometimes I get a weird noise at startup that seem to be coming from the power
supply (possibly specifically its fan). Sounds like a motor scraping against a
casing? The noise goes away after a few minutes. Been like this for a couple of
years.

But it's too much to ask anyone to diagnose something like this sight unseen.
Just noting...

Also beware that the
off-brand $32 power supplies are not exactly high quality. Your
original, even after so many years, is probably a better unit.

Okay. Someone emailed me in private with a similar comment (and many other
thoughts).

You're frequent crashes are probably software related. Given the
vintage, you probably have Win95 or Win98.

No, it's Windows ME.

Both were very buggy and
over time eventually become unstable. Of all the Win9x machines at
work, I've yet to have one make it more than 3 years without reaching
the point where it needed nuked and reinstalled. Of course, now they
get Windows 2000 installed...

Note to exray: It's a desktop computer.

To others saying a shop could perhaps better troubleshoot: The situation is not
crippling. Also, with my last computer, a shop took my money, kept the computer
a week, and failed to repair the problem. Sure, maybe I just had a bad shop. But
no, I do not have money to throw away and I am fairly savvy-engineering wise
(though computer hardware is relatively new). So I'm about somewhere that Bill
says. Namely, no need to look for a new rig yet and definitely inclined to
experiment on my own.

I doubt it's a virus. I use a modem and don't download garbage in emails.

Of course as others suggest, the problem could be software or something else I
haven't figured out yet.

I appreciate everyone's input.