Every game crashes?

[ROTENT]

For some reason, every game I play crashes 10 - 15 minutes after I load it and have no idea why because this never used to happen before.

My PC specs:

• 
  Intel Core i7-3770K 3.50GHz
  8GB RAM
  AMD Radeon HD 6800 Series
  2TB Harddrive

I've had this problem with GTA IV, Far Cry 3, Crysis 2, Bioshock 2 and Fallout New Vegas (basically all of the games I've played recently, I have more but I haven't played them in a while)

What can cause this problem? and how can I resolve it?

 

[The Stealthinator]

GTA IV is bound to have issues in Windows 8; I don't know about the rest of your games.

If your machine is not receiving sufficient cooling while in game, then whatever high-intensity processes running causing your machine to overheat, will crash.

Report idle and in game temps.

 

[Lyzands]

The same happens to me with Bioshock 2, random crashes. Far Cry 3 works fine though.