The BSOD error provided by the XPS is STOP Error 0x0000006f Session3_initialization_failed. Here are the first two results from googling it:
http://forums.techarena.in/windows-xp-support/867056.htm
http://forums.techguy.org/windows-xp/764365-session3_initialization_failed-bsod.html
They suggested trying Safe Mode to search for removed drivers, but in fact the drive on the PC makes a sickening thudding sound when I started in Safe Mode, so the reason why it can't find the drivers is physical and it was unable to complete Safe Mode startup.
I'm planning on getting around this by buying a new drive and cloning my working XPS onto it. The existing drive is a Seagate ST3160023AS, which is a 160G 7200RPM SATA 8MB Cache drive. I could buy that one still (the WD3160318AS seems equivalent also), or buy the WD equivalent, which seems to be part number WD1600AAJS. The advantage of the WD drive is that I can download their clone tool, which worked great the last time I tried it in the W98 era:
http://support.wdc.com/product/downloaddetail.asp?swid=119
