Hello everyone! I am newly registered to the forums, but I've been digging in the dark for quite some time.
Now, first of all I'd like to clarify that I've searched all over the forums for an answer before I wrote, and I tried many fixes, all unsuccessful.
The problem: With my EVGA 760 plugged in and Nvidia Forceware Drivers installed (no matter the version), any DirectX games cause a reboot at launch. No blueescreen, nothing, just the Kernel Power event and reboot just like that. If I'm using generic windows VGA drivers games come and go as they please, although they obviously don't work really well without Forceware Drivers, but they don't cause a reboot.
Here's what I've tried: Switched my GeForce with an old GeForce 8600GT (i know, archaic!) and the machine works. Games crawl but work.
Switched PSUs with another rig: Computer still reboots, so no PSU issue here.
Tried my EVGA 760 on another PC and... it works just like always.
Cleaned the whole rig completely, even dismounted the VGA to get at all the dust in it and the inside of the fans.
Bear in mind that I haven't changed ANY hardware modules for a year or so, and the problem appeared just a couple of weeks ago.
Software wise I've tried MANY versions of Forceware, did a restore to before this happened, switched OS to a different harddrive, ran memtest multiple times, reinstalled audio drivers and the HDMI audio as well since I was told it could mess it all up, reinstalled DirectX, ran a full scan on my HDD. Still, the problem persists and I'm really starting to despair. I don't wanna go out and buy some new hardware just to have it gathering dust with a problem that's still there.
Sorry for the extreeeeemely long post, but I'd rather be detailed and save you some time as well.
I'll leave my whole system SPECS down below, and thank you all for your help! :D
 
CPU: Intel Core i7 920 (no overclock) -> Coolermaster V6 Cooling Solution
RAM: 3X2GB DDR3 Gskill Ripjaws (memtest says they're OK)
Mother: ASUS P6T (It looks physically fine, no capacitors or anything out of the ordinary)
HDD: 2xWD Black 1TB 7200RPM
GPU: EVGA GeForce 760 2GB
Windows 10 Professional OS
PSU: Thermaltake TR2 600W (it's 1 and 1/2 years old)
 
That's everything relevant I can think of. Thanks again!
 

Hi , thanks for replying so quickly and for the warm welcome :). I went through your checklist as fast as I could.
So here's my results: Up your vCore .5 - Done, went even further but still no change.
Reseating the GPU and PSU cables - Done, even tried switching PCIE Slot, still no luck.
Deleted the old drivers on safe mode and reinstalled current forceware -
My CPU Temp is 42ºC with 1.240 Core Voltage, GPU is running at 36ºC with 44% fan(s) speed
I cleansed the CPU and reapplied Arctic Silver when I cleaned the whole thing up a couple of weeks ago.
I was running on 1201 BIOS, but I've now updated to 1408, with no different results :(
 
Thanks anyways. I'll keep trying whatever I get thrown, I don't wanna give up on it just yet

Yeah, I've done both of those. Tried an 8600GT on this Rig and this GPU on an i5 3550. Both passed with flying colors unfortunately (meaning I can't discard anything).
As for the intel test it passed without a flinch. Which is good, but sad :(

nico89sfx
Tried my EVGA 760 on another PC and... it works just like always.

No need to rma your card since it works fine in another pc. Have you tried re-installing windows 10 clean?

nico89sfx
Hi Sajin! That's maybe the only thing I haven't yet tried. I'm getting an HDD from another rig wiped clean so I can give this a try... May be a bit longer of a test than all of these. Wish me luck!

Good luck. 

How old was the other psu that you used? What is the motherboard temp reading inside the bios?

Do you have another video card that uses around the same amount of power that the 760 uses that you could test in your computer? If no, I would buy a brand new psu to try out.