It starts up and everythings fine to the point of the screen showing the Windows then all of a sudden it reboots? I've changed everything to Safe defaults in the BIOS/Optimized it etc...I don't think it's 1 Hardware problem as I've stripped everything down and exchanged parts short of the Motherboard and I've built plenty many Kits in my Lifetime BTA I could be wrong 
Assistance appreciatted ...
Assistance appreciatted ...