Originally Posted by Adamska
Hey thanks for the help, just found out that sometimes the graphics card fan doesn't start!
Yeah, overheating will definitely cause the problems you found. I suggest either an RMA of the graphics card (if it's not too old), a new card (if the budget allows), or an aftermarket GPU heatsink and fan. These can be had pretty cheap, even locally if you have a store around that has one and it supports your GPU. Best Buy carries some, but they're not the greatest, and provide limited support.