Display issue?

[[TC]►Ras◄]

The last couple of days, i've had an issue with my PC that suddenly popped up out of the blue.

Basically after it's been running for an hour or more, the screen will randomly go black and the "no signal" appears for a few seconds, and then it goes back to normal again, with a message popping up from the taskbar:
"The display driver nvlddmkm stopped responding and has recovered"

Although today it actually made the PC restart after it did it. In the event log the message above appears twice in a row rather than once. Also at the same time of this, it gives this in the log:
"Unable to recover from a kernel exception. The application must close."

Usually it happens if i'm having a program open (like LFS), watching a video in the browser or even browsing facebook.

So far there has been a big gap every time between it happening. Sometimes hours between.

What i have tried so far:

Reinstalled graphics drivers twice. First time i updated on top of the existing one and the second time i completely uninstalled the drivers and used Display Driver Uninstaller in Safe Mode to make sure it was completely removed, before installing the latest driver. Didn't solve it.

Updated the PC (Windows Update). Didn't solve it.

Unplugged and replugged my monitor cables into the monitor and the PC. Didn't solve it.

Disabled NVIDIA Audio related things in Device Manager (dont ask, it was a suggestion on Google) Didn't solve it.

Cleaned dust out of my PC, and especially the GPU by completely taking it out and blowing the dust out of it. Unsure if it helped, still waiting to see if it does it again.

My specs:

Windows 7 Home Premium
Intel Core i5 2320 3.00 GHz
NVIDIA GeForce GTX760 2GB
6 GB RAM
Corsair CX600M PSU

Any advice is appreciated. It is slightly annoying to deal with, considering it started out of the blue.