What types of games are you playing, I have the same problem with an hp computer, the chipset cant handle the games i throw at it.
A lot of different kinds of games, I will put a list here:
Euro Truck Simulator 2
Amnesia: The Dark Descent
Monday Night Combat
Red Orchestra 2 Heroes of Stalingrad
Slender: The Arrival
SCP - Containment Breach
Half Life 2
Zombie Panic Source
I used to play World of Warcraft as well but I uninstalled it a while ago before the problems started happening however it may have still had an effect so I thought I would tell you.