Reboots at stats, or reboots once first in game (ac97 cause)

Hi people I have a critical problem with BF.

Firstly - Specs :

P4 1.8
Radeon 9100 128MB
512MB DDR 2100
Gigabyte 8PE667 845PE Mobo
Avance AC97 Onboard Sound
DirectX 9.0

I have patch 1.4, and Windows XP. I can run the game without "hardware acceleration" enabled in the options for sound, but the game runs like crap, ie 5fps. It's unplayable (even at 50% bots), but I was sure my comp was good enough to run BF. I ran 1024x768x32, with all options up, but even when I put it on lowest resolution, it still ran like crap, maybe just a TAD better (still no higher than 15fps). I tried many things to fix it, and I disabled sound and it ran like a dream. But I need sound, so I enabled the "hardware acceleration" tab in the options. It then ran flawlessly @ 75fps even in a battle with 400% bots. At this time I had just reinstalled so I was playing the "operation battleaxe" level. But when I finished the level and it came up with the stats screen, the computer instantly restarted. So I went into advanced windows options and made it show the BSOD instead of instnatly restarting. So I played the first level again, and it came up with the stats screen, but then instantly went to a BSOD saying "driver IRQL is not less or equal", with the file causing the problem being alcxwdm.sys - my Avance AC97 sound. I was using the *latest* AC97 drivers. So I rolled back to earlier ones and I have now a different problem. When i get into the menu, the game just instantly quits to desktop. I have tried everything like turning down acceleration in dxdiag, even to no acceleration, it just crashes to desktop the second I get into menu. The ONLY combination that actually lets me play a level is the *newest* drivers with the full acceleration in dxdiag, but then it reboots when the stats screen comes up. Does anyone know any possible solutions to this?

Thanks