Minecraft is constanly crashing.

I have just updated my minecraft to 1.4 but it seems when I go on to my minecraft and enter my world my minecraft crash's. I've put on snoper settings but it dose not help. It also dose this when I try and create a new world and when I join a a sever and try and get a new texture pack. As you can see my minecraft dose not work at all. My java and windows is 7.