I say, I say, I say... my computer won't boot

Then how do you use it?
I can't

Further updates on the health of hughanchor the computer, since you seem to be so desperately interested. After a very healthy day on Saturday, things took a turn for a worse overnight. I got up this morning to find a new windows XP stop error -- something about a bad IRQ level, or something (actually, it was "IRQL_NOT_LESS_OR_EQUAL"). I started trying to see whether the memory was the cause, so I started moving the memory around. This only seemed to make things worse, so I put in the old memory I had before I upgraded this summer. No joy, in fact the machine would consistently reboot after startup almost immediately: just after beginning to boot windows, just before the "Windows loading" screen would appear. So it now seems unlikely that the memory is to blame, since I've tried several different lumps of memory in it, and unless they are all broken, then it should be fine.

In fact, I managed to boot from the install CD to a prompt and explore the hard drives quite happily. I also downloaded and burned a copy of "memtest86" on my laptop (the mugwump2, god bless all who sail in her), and got hughanchor to boot that and run memory tests for several hours with no errors detected.

OK, so where does this leave us? Certainly, the computer is in reasonable shape, modulo the fact that it can't boot up its regular operating system. After my initial wrong accusations, the power supply seems fine (I checked it with a multimeter and through CMOS): although VCORE seems rather low at 1.44V, I think this is just a feature of my machine. CMOS also tells me that the operating temperature of those components that are measured is not too high (about 36 degrees C, it seems). Memory seems to be OK. Disks had a reasonably thorough checkdisk run on them this morning before XP started refusing to boot. Of course, any or all of these assertions could be hopelessly wrong, and may be the cause after all.

But there is one possible suspect who is beginning to look more likely. Can you guess who it is? It is my once trusted graphics card. Consider the evidence: the generic stop errors I've been encountering can be caused by bad memory anywhere in the system -- including the graphics card. The problem currently manifests itself as windows is about to start up -- which is when it switches graphics modes to put a pretty logo up while it loads. Text only applications, such as the memtest86 programs, seem to run happily with no problems. And there's one other symptom I haven't mentioned: now, during the bootup process, my monitor flashes up a brief error message (from the monitor itself): graphics mode not supported: Horizontal 31.2KHz, Vertical 59.5Hz. Which has never appeared before.

So, the chase is closing in. It is starting to look like the graphics card is at fault. Or is it? Some or all of these errors could also be explained by a faulty motherboard, (maybe the dilithium timing crystals are off, which is causing various synchronization errors). Perhaps it could be the L1 or L2 cache on the processor? Or maybe something I've tried to rule out, like the memory, is actually the problem?

The scientific method here is to replace each possible component in turn, and see if things improve. I was fortunate to have some extra memory lying around so I could do that test, but I don't have a large stock of spare graphics cards, motherboards or processors lying around. If I did, I'd probably build another computer with them. Oh well. Thank goodness I have a laptop (try searching the internet for debugging information when your machine won't even boot...) and a collection of DVDs to catch up on. I'm too busy to give this my full attention, with paper deadlines and some brief international travel coming up in the next few weeks, so I doubt I'll have the full answer any time soon. Maybe I'll have to admit defeat and get it taken to a specialist.