Well as you're a computer guy, maybe I will burden you with the symptoms that warned me of eventual failure?
The first thing I noticed a few months ago was that the PC would shut itself OFF instead of going into hibernate after 3 hours. So I disabled hibernate. The problem seemed fixed.
Then a few weeks ago the PC would suddenly quit as if there had been a power cut and would reboot itself. Then the next day it took 3 tries to load the desktop, but was ok afterwards. The next day it was the same but kept quitting suddenly and auto rebooting. Even though I had set the bios for the PC to remain OFF after a power cut many years ago.
I decided to try cleaning the PC's internals, since I had not done so for a long time. There was a lot of dust in the heat sink/fan housing of the video card as usual, it seems to like to store dust in the spaces.
But then afterwards the PC wouldn't reboot at all, and all that would happen was the light on the cd drive would constantly flash as if the PC was trying to boot from there.
I had replaced the power supply years ago, and it had lots of extra wires that were extra long. Once before one of the wires caught on something when the case was closed, and then just moving the wires about fixed things and it ran ok afterwards. But not this time. Still no hdd activity.
Since the hdd seems to be dead, my last try will be to try a different power plug since there's always a chance the one currently connected might be damaged due to being strained when pulled on by closing the case.
But once that fails to fix things, as I expect it will, then I'll consider your advice to buy a cheap pc, but I might splurge on a ssd, since I don't trust the sata hard drives too much. They seem much more fail prone that the old pata's, to me.
Then, when I win the lotto, I'll get one of these:
http://www.ncix.com/detail/ncix-pc-impa ... merReviews

(Well, I can dream, can't I?

)