Faulty GPU or graphics drivers?

AMD FX4100 quad core 3.6GB
8GB 1600 Kingston hyper X DDR3 RAM
GTX 560 (palit) 2GB (non Ti)

Right, this is a long story. In 2012 summer I bought myself a PC from pcspecialist.co.uk. Almost a year later I encountered a problem where the PC would crash when playing 3D games (before you ask, no. The temps are fine). It would also sometimes crash when using it for general purpose low intensity tasks such as web browsing Assuming this was a GPU issue, I sent it off to PCS (PC Specialist) and they sent it off to "the manufacturer" (I am guessing this means palit)

I got it back a few weeks later with no description of what was wrong with it but PCS told me they ran their standard procedure check on the card (I do not know how in depth this is). Anyway, I hooked it back up to my PC and booted the machine up. It no longer crashes in 3D games although it does still randomly crash

I am now not sure weather this is the GPU itself of the drivers, or maybe something else: When the PC crashes now, the screen will freeze up and stutter along about 2 to 3 frames before pausing for a few seconds, and then the screen goes blank and the PC reboots. Sometimes the PC will not crash, sometimes it will recover. However when it does this I find it behaves oddly. Things like making the flash youtube player fullscreen will take 2 seconds and when I toggle in and out of 3D applications like TF2, the PC will also stop for a few seconds to think about what it is doing

I have never experienced the mouse freezing up ever before, Microsoft did a good job of keeping that separate to everything else. Meaning this must be somewhat of a large problem

Things I have tried:

- Checking the temps

- Reinstalling the OS, twice

- Downloading the latest drivers

- Shouting at the monitor

- Looking inside the PC for things such as places where it might be shorting (I don't know the insides of the PC like a pro so I could have easily missed something, but there was nothing obviously wrong with it)

Things I have not tried:

- A different GPU (I only have one)

- crucifying my PC (fire hazard)

- Take everything apart and put it back together again (don't really know how) Any suggestions or theories on what is going on or how to sort this are greatly appreciated

If you need any more information I am happy to give it to you as I do not want to have to buy a new PC

But, it one good thing did come from all this then it's the fact that I got to see my GPU failing to run portal 2 in the mostest awesomest way! (this was before I sent the card off to PCS) http://tinyurl.com/obunea8 <-- Click this for a video of my PC giving off a light show!

Try running the game off a different hard drive, the HDD may be corrupted.

If possible, try using different ram, and a different GPU. 

Before I saw the video, I thought it could be a hard drive problem.

I still think that might be the case. 

Mainly because its the cheaper solution to fix. Haha.

 

Try installing to a different hard drive, if you have one lying around. 

If that doesn't work, then its the GPU. I don't think that its a driver issue, It's most likely hardware.