The following is what the event viewer says, after the computer auto-rebooted:
The driver nv4_disp for the display device \Device\Video0 got stuck in an infinite loop. This usually indicates a problem with the device itself or with the device driver programming the hardware incorrectly. Please check with your hardware device vendor for any driver updates.
I was playing the mod on maximum settings, although there wasn't any major slow-down before this error, so I'm assuming either I managed to knacker the card or drivers somehow, or this was just something that was bound to happen eventually no matter what. Drivers and video cards don't last forever...
I didn't have anti-aliasing maxed out or grass shadows. Just used the default maximum settings, plus maxed-out vision distance.
Please help me...

EDIT: Here are the computer specs if it helps.
Card: NVIDIA GeForce 8600 GT
Main Driver: nv4_disp.dll
Version: 6.14.0011.6267 (English)
BIOS: Award Modular BIOS v6.00PG
Processor: AMD Athlon(tm) 64x2 Dual Core Processor 5000+, MMX, 3DNow (2 CPUs)
Memory: 2046MB RAM
Page file: 3100MB available
DirectX Version: DirectX 9.0c (4.09.0000.0904)
Using XP with Service Pack 3 installed