[i've been possessed by lil pun] Computer problems :(

So I've got this four-year-old Dell Dimension 8200, running XP. A couple of nights ago I flicked off the monitor and went to bed; when I turned it back on the next morning, I saw not my desktop but a blue screen informing me that Windows had been shut down to prevent damage to my computer. "WTF?" I lucidly thought, and restarted, as the screen instructed me to do since this was the first time I'd experienced the error. Since then, the closest I've been able to get to a successful boot is a brief display of my desktop and icons before the monitor goes to that not-quite-off gray color and won't be moved from there. I've tried the "Last Known Good Configuration" option at startup... no go. I've let it run through its checkdisk thing, when it gets that far; no help. Even safe mode doesn't work, nor does booting to the command prompt.

The error screen looked pretty much like this one:

except I believe my error was 4F, not 8E. Also, during startup, it says things like "The amount of system memory has changed." and "Decreasing available memory." (before telling me to strike f1 to continue or f2 to run setup.) It's also said things like "Memory address line failure at 9827406, read FFFFFFFFF expecting FFF0430FF0575m," which is obviously not a quote but gives an idea of what I'm looking at. I've also, once or twice, gotten as far as another blue screen which tells me that a hive, which I believe was located in the windows\system folder, is missing or corrupted - something like this: "Stop: 0xc0000218 {Registry File Failure} The registry cannot load the hive (file): \SystemRoot\System32\Config\CorruptHive or its log or alternate. It is corrupt, absent, or not writable."

The Googling I've done on the topic seems to indicate that this is an indicator of either bad RAM or a bad video card. Anyone able to narrow that down for me, or point me in a different direction, so I can spend as little as possible in fixing this?

Thanks so much.

 

Update!

R2K's rock-solid diagnosis of bad RAM was confirmed by geeimsobored's excellent Ultimate Boot CD, which I highly recommend, unless you have to download it on a 56K modem like me. Anyway, my RAM failed the vast majority of the memory tests. (I couldn't experiment with removing one stick to see what happened because my system required a pair of sticks in order to function at all.)

So, instead of just getting some piddling little RAM sticks, I got a new bare-bones case with the intent of swapping over my Dell's hard drive, CD drives, modem etc. This new one's got a 3 ghz P4 processor with an Elitegroup RS400-A motherboard.

(Can you tell we're approaching another problem here?)

Anyway, I got my drives in and I'm getting another stop error screen before XP has a chance to boot. Different error though - instead of 4F, it's 7B. The blue screen advises me to run chkdsk /f - as if that were an option. Just to find out if it's a bad hard drive, I plugged in a different, older one I have, which works, and got stop error A5, which gently informed me that this system's bios is not ACPI compliant. That told me nothing besides the fact that the hard drive I actually want to use probably isn't the problem. (I ran the memory diagnostic from the boot CD again and everything passed this time, so I guess it ain't the RAM either, which is good 'cause it's brand spankin'...)

Is this a typical thing when plugging used hard drives into new systems? Must my master hard drive be clean and formatted? Do I have to "flash the BIOS"? Do I have to buy it dinner first? Does it care if I shave?

Jesus, I need to go to bed.

Anyway, I really appreciate any guidance anyone can give me. You guys rock.