Solved constant auto rebooting

[vv211]

I just finished building my own pc and installed windows 7 pro x64 (legal copy) on it.

specs:
mobo - Gigabyte GAz77 D3H
Boot Drive - OCZ Vertex 4 128GB SSD
Data Drive - Seagate Barracuda 1TB 7200 RPM
CPU - i7-3770
RAM - Corsair Vengeance 8GB (2x4GB) 1600 MHz
GPU - Sapphire Radeon HD 7950
PSU - Cooler Master ZU-600B single rail, modular, 80+ Bronze (600 Watts)
Montior - Dell ST2220L (connected through HDMI)
Keyboard - Onn Wireless USB keyboard (Walmart's brand i think)
Mouse - Cooler Master Sentinel Advance II

Programs I had just installed:
Daemon Tools Pro (not so legal, though i never had any trouble with it on my laptop)
TeamSpeak 3
Origin (with BF3 and BF 1942)
Chrome
Notepad ++
Gigabyte Utility Software and Chipset Drivers
MSI Afterburner

All the drivers were up to date, and nothing had ever been overclocked yet.

It first happened when I was switching some USB peripherals around because one of the ports wasn't working. After the reboot I installed the USB 3.0 drivers from the Gigabyte disc and the port was working. Everything worked fine for the next 30 minutes or so. It rebooted again while i was googling where teamspeak places its bookmarks, and then has rebooted again within 15 seconds of logging in, sometimes even before POST or about 5 seconds into entering the BIOS.
I've let it go a couple times and it would reboot like 5 times before i finally hit the power button, each time there wasn't enough time between reboots to even show anything on the screen.

Also, the monitor will slowly dim and then slowly go back to regular brightness at the login screen and then again after logging in. plugged in directly to the gpu

 

[vv211]

Late reply, sorry, but the cause of this was a faulty reset switch on my case.

I had RMA'd my motherboard, and when the new one came it was still restarting, on the verge of RMA'ing my CPU i read on a forum somewhere that someone had a faulty reset switch and was giving them these same symptoms. I unplugged the reset switch and haven't had any more issues with this.