Something is causing my PC to freeze and crash

terminator123

Honorable
Sep 16, 2014
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10,990
Hi,
I have built a new computer recently and it's been running brilliantly until I installed my old graphics card into my new computer. My graphics card is a GTX 660 and before I was using on-board graphics.

When I play Arma 3 or Garry's mod or maybe other games (I'm not sure) sometimes it happens after about 5 minutes of playing, sometimes 1 hour or more. My game suddenly starts to go really slow and the sound deteriorates, then my PC freezes because of this problem when Arma 3 or gmod is running, and my internet just disconnects. I then HAVE TO restart my whole computer

I don't understand why this only started happening once I've installed my GTX 660.
It only happens when I play games (at the moment them 2 in particular)

I was wondering if somebody can help me out as I'm quite concerned.