Random flickering green pixels and computer freezing

[moodseller]

So I've got this issue today, but it might have had a chance to occur a couple of days before since I wasn't playing any games and basically not putting load on my graphics card. The problem is, that whenever I launch a game, my screen starts flickering green pixels randomly across the screen after playing for a minute or so. I didn't pay attention to that at first, cause it eventually "went away" after happening for the first solid 5 minutes, however, now playing another game, the same thing happened again and it lead to a whole computer freeze, the sound went off and I wasn't able to access anything at all and had to reboot it. I have found a couple of pictures on the internet that represent the situation of how it looks but I can take my own picture as well.

My situation looks very similar to the picture above, except there are usually much more green pixels and much more scatter everywhere.
P.S I've noticed texture flickering and artifacts the first time it happened ( the time that it went away after )

I'm using:
NVIDIA GeForce GTX 560
i5-3570k OC @ 4.5ghz with 1.185V + Hyper evo 212
Z77A-G45
Codegen 500W PSU

Might it be the GPU that has became faulty? It's a couple of years old, maybe 3 to 4 or even more. The idle temperature is static @ 45 C and tend to rise to 60-65 on load.

 

[Minemand]

Have you tryed booting into safe mode and completely removing the GPU driver and installing it again?

 

[moodseller]

I have tried firstly updating it and then re-installing it. I don't think its the driver that's causing this cause it was fine before, haven't touched the driver before this happened

 

[moodseller]

I managed to take some pictures of the screen once the freeze happened again:

I'm running dual monitors, this only happens on the main one, where the game is played. The sound most of the times freezes too, either way though, restarting the PC after the freeze is mandatory