Replacement PSU for Compaq Presario?

My mom's rig (Compaq Presario SR1230NX) has been ailing for a while, and I think I figured out the problem (besides the lack of RAM and onboard video).

The PSU is crap. I'm not sure of the wattage, but I just checked the 12V rail and it's at 11.37 (that seems way too low). Here's what Speedfan says (I'm not folding right now; suspended on this rig pending some better fans).

vCore: 1.65v
+3v: 3.33
+5v: 5.12
+12v: 11.37

-12v: 1.31
-5v: 5.11
+5VSB: 5.40
VBAT: 3.30

What would people recommend? I'm considering a Bluestorm, pending Microcenter's stock and I also have to see if this board will take it. Board is an Asus A7V8X (I think so; Asus' website is being stupid). CPU-Z identifies it as "Kelut" with a VIA KM400 chipset.

Were you able to confirm that 11.37 with a DMM? And is the current PSU standard ATX size or one of those tiny MicroATX's?

Wait, is the computer crashing or is Windows just acting funny? If it's the latter I recommend a spyware scan before a new PSU.

Regardless, what brand of PSU does it currently have? I know HP and Dell put Delta's in their boxes, but I don't know about Compaq. If it's a Delta it's probably rock solid and the problem lies elsewhere...

It's usually just Windows being laggy, but it has crashed twice today (of course, it's automatically my fault ). All scans come up clean. There is a heat problem; this thing is stuffed in a corner with boxes of papers et al around it and the front intake is very tiny.

Not sure about the PSU specs; this comp is in some sort of under-desk clamp that one of her friends jury-rigged with some bolts (so I can't get the case out without some maneuvering). My DMM has disappeared...I'll try to find it tonight. far as I can tell the PSU is standard ATX (I'll confirm that probably tomorrow as I also have to check the RAM slots and probably clean the fans as well).

*wonders why all the PC tools I bring into this house end up vanishing*

It might be clogged up with dust inside, which might be what's causing the heat issue. If you can convince your mom to let you open the case, you can clean up any possible dust.