My PC keeps crashing while playing multiplayer - BF4

ok my system is as follows

Windows 7 64 bit

intel i7 920 (bloomfield)

sabertoth X58 MB

6GB corsair RAM

Navidia geforce GTX 660Ti

with SSD.

RAM usage can be not far off 100%, i have 2 allocations for VRAM.

and just to confirm, it crashes the whole pc out, i have to hard reset and reboot to get back in to the OS and i cant see anything once it happens (as in i see the game as it was once crashed, but unable to switch to tools to check on things)

I have tried a few bits you have told me about below and I shall report back once anything comes apparent

ok so as it stands right now, i have tried/done the following:

set the in game audio to headphones.

ensured that direct x is updates, and teh MS .net framework is also uptodate

disabled the NVIDA high def audio.

the security permissions of the origin folder is set for everyone to full control

set the nvidia contol panel phyisx to my GRD card and then did repair

uninstalled all the C++ and reinstalled as stated. had an issue but repaired that one.

all my settings are low as that was one of the first things i did when i started having this problem (from the start!!!)

and all that, it just crashed on me !!

i will now give the uninstall and reinstall of punkbuster

and run as an admin and look at going backwards on the the GFX drivers

thanks

sid

PS... i have played on campain with no issues at all, so would seem ? at the mo that it is MP only!?!?!