Going off Toasty's tangient..
what sound system is the game using? Does the Mod change Music Format or introduce new music?
For instance.. if the game uses Miles Sound System.. there are many DLL's for MSS..
on Vista / Windows 7.. MSS DLL may not work correctly and cause a cascade memory leak as well.. which may be tied into DirectX which could give a false reading into the Video card.
as example.. KOTOR and KOTOR II games
KOTOR MSS DLL works fine on Vista / Windows 7, however the MSS DLL in KOTOR II causes KOTOR II to shutter and play without sound.
by replacing KOTOR II MSS DLL with KOTOR MSS DLL, KOTOR II plays flawlessly.
Toasty may be on to somthing there..
but again as Rod stated I would look at the Mod again, unless other programs are causing errors on your system when on other machines they work fine..
to me it sounds like time to replace the machine with something more modern.. but besides that, I think that the Mod is overtaxing the Vid card.. and referencing SFC and crashing, if it is with a Mod installed.. again my OP Enhancement Pack has high poly / res models that your card would be hard pressed to handle smoothly.
Different things to consider and think about.