Ok, about a month or two ago now, I got a new mobo and cpu. asus m4a78-3 and a six core amd.
Neither of those is the problem I'm pretty sure.
My video card is nvidia 260 gtx and psu is called iceberg or something, lightup 680w power supply.
Whenever I run windows experience rating tool the first test is direct3d aero 9 assessment which causes my system to completely power down, I have to use the switch on the back of the case to turn off power then wait, turn it back on before it will power up.
I've tried taking the video card out and running the test with onboard video and it worked fine, obviously though, there is still something wrong with my system.
I don't have an alternate power supply to test with, or any usable video cards to test with ie. have power supply connectors on them.
I could be wrong it could be some other issue, but the ammount of info on such occurances is slim to none, I've been searching frequently for the last month or so and trying to talk with friends that are more knowledgable than myself but no joy so far.
I have the latest nvidia drivers, and I also used driver cleaner to make sure there are no ati drivers present (m4a78-e has onboard ati). That didn't change anything, was one of the first things I tried.