Program Issues

Okay so I just built a new ground up system, and am having a really big problem, my internet (firefox) and multimedia runs well but almost all other apps get this wicked lag where they freeze/lag and then start again then freeze and just keep doing this, in some I get clipping of the audio. The applications I know this happens in are Guild Wars, Google Earth, Warcraft III, Rise of Nations.

I reformatted, and tried re-installing all the newest drivers, flashed my bios to the most recent version, and have kept an eye on my temps, nothing gets too high, the weird thing is I tried using nVidia's stability test and the crashed my system and made it restart

Motherboard: ASUS P5N-32SLI SE Deluxe
PSU: Hiper 580W
Video Cards: SLI Gigabyte GV-NX76G512P-RH
RAM: 4GB (2x2GB) DDR2 667
Processor: Intel Dual Core 2 Duo 6600 2.4GHz

does anyone have any ideas?

BTW my name is Greg and I hope that I can help out some around these forums as I get better acquainted with all of you

Greg

 

Bad Ram connects else/or are the progs you mention are able to run on dual core
Just thoughts others may have better ideas.
Cheers
Robert