Seemingly random games crash pc

A friend of mine has been having problems with his pc crashing when he starts up games such as 

Portal 2, Dirt 3, Farcry 3,  Borderlands 2, Warframe, Saints Row: The Third, Red Faction: Armageddon and GTA 4

His drivers are up to date and other games run great, but the list of games above crash his pc, have tried multible crash fixes for them and none seem to work, was hoping you folks could help him out.

http://pcpartpicker.com/user/Metlearm/saved/2IKq his build

 

any sign of crash logs on any of these games you have access to? 

the only thing that comes to mind is using a 970 board with the fx 125w processors. maybe try down-clocking the processor to 3.4 or 3.5? see if they persist? verify the integrity of game cache on the steam games? 

ill look into all of that somtime tomorrow, thanks