You do not provide much information in the post, but here are a few things you should always try in a matter like this. The first and most common thing that causes something like this would be custom modded profiles. Try running Minecraft using a totally vanilla profile and see what happens. The only other thing I can think of off the top of my head would be to update your Java version and possibly your graphics card driver. If this doesn't work, please reply showing a screenshot of the log Minecraft provides you when this happens. Best of luck!
You do not provide much information in the post, but here are a few things you should always try in a matter like this. The first and most common thing that causes something like this would be custom modded profiles. Try running Minecraft using a totally vanilla profile and see what happens. The only other thing I can think of off the top of my head would be to update your Java version and possibly your graphics card driver. If this doesn't work, please reply showing a screenshot of the log Minecraft provides you when this happens. Best of luck!
- Lee
http://www.Youtube.com/Firehound57