I would firstly update your graphics card driver. It may be that it didnt come with the latest.
The other thing that might be happening is that your pc might be over heating. Can you do a visual check to see if all the fans are working?
One thing to do is to make sure that if it does crash it doesn't reboot automatically. Go into Control Panel. System. Advanced. Start up and Recovery Settings. Uncheck Automatically Reboot.
If a crash does occur you might get an error code that will help diagnose problem.
hope this helps