The minecraft launcher works launcher (1.6.11) but when i hit play it loads the Minecraft 1.8.1 bu then right before it says Mojang it goes black and it works for my brother, PLEASE HELP ME

I thought minecraft was going to run smoothly, and I was going to play with my brother

But it started up fine then when it went to Minecraft (not launcher) The screen when black and will not let me back on I tried EVERYTHING.

Step 1.Open up minecraft normaly

Step 2. Hit Play

Step 3.Screen will go black and it will Crash (for me)