Of all the Stop errors Windows can show, *** HARDWARE FAILURE *** is probably the worst one.
*** Hardware Failure
Memory parity check failed.
Call your hardware manufacturer.
*** The system has halted ***
So I'm currently running a full comprehensive multi-pass memory test (courtesy of System Rescue CD) on the computer, trying to figure out if it's a hard failure or a soft failure (the computer had been running for over a day straight in a warm room, but not warm enough to overheat), and if so exactly which DIMM needs to be fixed. Meanwhile, I'm glad I've got my school files all on this computer, my SD card, one of my USB sticks, and an external hard drive, I've got an extended warranty on that computer, and I've got my Tablet PC to use in the interim.
I've been in the case of that computer so many times, though, I'm not entirely sure if they'll still honor the warranty. (It's one of those computers designed for easy upgrades- it's got release buttons to open the case without a screwdriver, footpads on the side to set it down gently easily, a catch to hold the case open, latches holding down all the components so almost nothing standard to modify requires a screwdriver, etc.) At least if I can pin down which memory chip has blown- assuming it's a reliable hardware failure- I'll be able to fix it just with new RAM... and probably more of it, now that I'm using Photoshop. I wasn't really budgeting for it, though- oh well, bad luck is like that.
The memory test didn't find anything on the first pass, but I've switched it into super-comprehensive mode now, trying to recreate the chance it will reproduce the failure. I guess I'll just go back to sleep and let it run- I'm pretty sure MemTest86+ will cheerfully run until I tell it to stop, so if it's a problem that requires the computer to run for a wihle, that'll give it a chance.
And if I can't recreate the problem, what can cause a transitory memory parity check failure while shutting down Windows, when the computer had before shutdown been running as well as usual?
**edited to add**
Well, that would explain it. Note to self: Before assuming that the part that claimed to fail actually failed, assume that the recently-added hardware (there's no network cable up to my room- it looks like "300 feet of cat5" is on my shopping list now) is the actual source of the problem.