EVGA 770 repeatedly crashing/rebooting PC

[JonD7]

Hello all.
I recently purchased an EVGA GTX 770 (to upgrade my old ATi 5850 which still works with my hardware btw) and it doesn't crash when gaming(in fact I can play for 3 hours+, fine) but as soon as it idles or I'm browsing the web(latest version of Firefox) and listening to music... it shuts off and reboots.

I don't get a BSOD or anything, I've checked Event Viewer and it says it shut off unexpectedly.

Event ID 14
Microsoft-Windows-Kernel-Power" Guid="{331C3B3A-2005-44C2-AC5E-77220C37D6B4}

I found this on Google
http://support.microsoft.com/kb/2028504#method3

I have seemed to try everything... resetting BIOS, uninstalled and reinstalled Firefox/Nvidia Drivers and the problem still persists.

I have tried an RMA and the 2nd one does the same thing, which tells me theirs something else causing this.
Also I have kept an eye on the voltage with HWMonitor and I don't notice any strange voltage spikes.

This is the one I have...
http://www.newegg.com/Product/Produ...301&nm_mc=AFC-IR&cm_mmc=AFC-IR-_-na-_-na-_-na

I've been using the card for 3 hours now, with no drivers whilst listening to music/browsing the web on Firefox and no problems.

Could this be a driver issue or is it possible that these problems are occurring because my CPU is at stock and this particular GPU is overclocked?

Thinking of just sending this card back and getting my money... then building a new PC next year.

 

[Wraith]

Could you give us a list of hardware your using please including any OC's?

How old is your current PSU?

 

[JonD7]

Could you give us a list of hardware your using please including any OC's?

How old is your current PSU?

My hardware is in my signature... it's not over clocked as I'm still a noob honestly, also I don't have a PS/2 keyboard so I can't really access the Bios.

My current PSU is the Corsair TX750, I built this PC in March of 2010.
I think it'd be strange if it was my PSU as I don't have any issues with my ATI 5850.

but I do have a Corsair AX850... my dilemma though is the simple fact that I am disabled and can't switch it out by myself, I can ask my brother but if the new PSU(I'm saving for a new build) doesn't work, he's not going to reinstall my old PSU, lol I don't want to lose out on $200 just because of his lazyness... if it's %100 percent a fault with my PSU, I wouldn't care though.