Call of duty 2 shuts off my computer

[kosmiq]

I am not 100% sure but it could be your PSU. If it has the same problem as the A8N32-SLI Deluxe it might not work very well with Antec PSU's. I have no idea why that is but a real good PSU is recommended to both anyway. I know that the Antecs are great generally but it seems as if they are not up to the task when it comes to the nForce X16 chipset.

I would recommend Seasonic S12 500w or even better the 600w version as they both have been confirmed working really good with both those m/b's.
Other than those OCZ Powerstream 600w has also been confirmed working very well. There were a few other brands too but none of them I had never heard of (they're not even avaible here in sweden).

Considering your setup with that motherboard, 2x7800GTX 512 and the other stuff a Seasonic is recommended anyway.