PING: any techie/computer geek

[Wolfpack]

I've encountered a very serious problem with my computer. Every time I start it up, I get blue-screened just as XP is about to bring up the desktop, informing me there is a "STOP: 0x0000007F" error. I've done research on the matter and the first parameter of the error message says "0x00000000" which Microsoft says seems to be related to bad memory (DIV error of some kind). The totally odd part is I don't think this is correct. The reason I say this is because, as a matter of ruling things out, I plugged in an older hard drive (which I had replaced because it was having boot sector issues, but was otherwise fine, loaded up with XP and all that) and did not encounter the error (it's what I'm running on right now to type up this message). All other hardware is unchanged from the original setup.

Here's one additional point. Recently, MS released a new security update and my machine did the automatic download and install before it shut down last night. The blue screen came up when my wife started the machine this morning. Could there be something bad in the update that screwed things up? I tried to see if there was a way to uninstall that update, but it isn't listed in the "add/remove programs" section. I ultimately tried removing SP2, but that didn't solve the problem and now I can't get SP2 re-installed because Windows Update doesn't work in Safe Mode.

So, do I really have a memory issue, or do I have a hard drive issue or something else? Do I need to re-install XP? Would it matter? Or would I need to (for the second time in six months) get another hard drive and re-install everything? Any other ideas or points I should consider?

I should note this is a DIY box with the following setup:
Intel P-IV 1.4 GHz
Crucial 256 MB RAM
Shuttle AV40/R motherboard
Seagate 160 MB HD (the one encountering the error)
Western Digital 100 MB HD (the subsitute)
SB Audigy sound card
Memorex 52X CD-ROM
HP 9900j CD-Writer/DVD-ROM
Win XP (was SP2 on the Seagate, SP1 on the WD drive)

Any thoughts would be appreciated. I don't want to rely on this replacement drive too much because the boot sector issue will likely rear its head again at some point.