[CRASH] Computer crashes during every game.

At random times in any game mode (pvp, bot games, casual) my computer will freeze. Before the freeze there is noticeable frame drops throughout the game. This happened the day after updating drivers, is this related? Longest I have stayed in game was 18:18 although most games crash in first 5 minutes. To try recreate this problem: open league of legends and launch, login, search for game, play game for some time, game will freeze and need rebooting via power button. Crash occurs every game at least once, maximum crashes in one game so far is two. I have played LoL since mid season 4 and this is the first I have encountered such problems. Any help is Appreciated.