Game keeps crashing

For the past week the game has been crashing (A software error has occured) primarily when I try playing on a world or a server barely managing to get past the loading screen. The game also crashes when I sometimes go into the options, skin options or even during the Mojang loading screen. Basically wherever.

I have checked for corrupted data and I've even redownloaded the game twice. But effectively this has made it impossible for me to play at this point. So I'm at a loss about what to do about this.