Game crashes and make my computer restart

[Bricked Up RN]

Specs:
i7-4770@3.4GHz
Gigabyte GTX 970 Mini-itx edition
12 Gb of Ram
Game is installed on my 2TB HDD

I just bought this game because I loved Dirt 2 & 3, now about 20-40 minutes into a session, my screen goes black and my computer restarts without any error screens or anything. Could be important to note that the game tends to crash when playing on Greece's stages. I used the ultra preset setting but lowered it to high since it crashes less. I also have this problem with the newly released Dirt 3: Complete Edition without finding any fix. It only does this with Dirt Rally and Dirt 3: CE, could it be related to the fact that these games were optimized for AMD GPUs?

Hope you guys will find a fix soon, this game is so fun!