T1B

I'm wondering if my computer is in its last throes of usefulness.

Let's look at the hitlist:

• When the screen saver kicks in (black screen one), it sometimes doesn't reenage the system and I'm forced to reset. This happened 3 times yesterday.
• Used to be able to multi-task, but now the machine slows down a lot when I try.
• Runs at a hot 134 degrees when on
• Burning a CD is a hit and miss affair. Will sometimes stall at 50 percent completion for minutes on end until it finally catches up and completes.

We upgraded the computer 3 years ago to a 1.7 celeron with 512 megs of RAM. I've mentioned that my wife finally believes me that the computer needs to be replaced. Are these warning signs of things wearing out because of the high heat in the case? Does that cause RAM and such to wear out?

That's pretty warm, especially for a Celeron. I'd suggest replacing the fan at the very least.

like Donovan said that is hot.
try blowing out the case with some air.
betcha the processor fan is caked with dust.
the other things you mentioned could be caused by some appilcations running in the background like spyware etc..