Problems with new PC build please help!

About 4-5 days ago i purchased all of the components to build a gaming PC rig and enlisted the help of my friend for the build.

The parts

Cm storm trooper case 1tb WD black hdd Amd fx 8350 4.0ghz 16gb of Kingston 1600mhz ddr3 2 x evga gtx 660ti's Sabertooth 990x mobo 850w 80+ certified modular PSU Lg 24x DVD drive 24 inch 1080p 240hz monitor Razer taipan mouse and anansi keyboard.

Blah blah.

But here's the issue, we got all the parts together and successfully booted to bios. Popped the windows 7 installation disk in and ran into a weird issue, the computer would reset during random times. And would sometimes hang and reset when we would move the mouse or keyboard. So we tried different USB ports and a different mouse and keyboard to no avail.

Ruling that out as the issue. We checked all the hardware/cables and made sure everything was up to snuff and had a friend take a 3rd look. Booted back up and bam. It was doing it again, and it wasn't fully restarting. It was black screening and going back to the

"Press delete to enter bios" screen

So I thought the motherboard was suspect. Swapped that, the CPU and the ram out just to cover all the bases.

Put it all back together, and fuck me the same thing happens. Tried a different monitor. Swapped the CD drive for one I know works.

The only part that hasn't been replaced yet is the case and the PSU And GPUs I have tried both GPUs independently and same thing. Its reeeealy strange what is going on and I am at a loss and am hoping reddit can help me.

Any suggestions would be amazing! And if I reach a solution I will surely gift the kind redditor!