so i have built a decent ammount of pc's and i just got done building one for my gf. It works beautifully except for 1 thing every now and then when shes on the net or playing minecraft or something her screen will go black and we will have to restart the pc. Now this happens for about 3-4 times before it stops and does not happen again. Can anyone give me some insight. I'm thinking that the gpu may be bad but thats all i can come up with.