I just bought  Alienware 18MX laptop last week (NVIDIA GTX 780M  4G Graphics card ) and I have a problem, my screen goes black while in the middle of my game for about 10 seconds and then returns to normal.

When it goes black I can still hear the game but can't do anything. This problem occur around twice a day.

Is it something serious? please help me out.

Thank you for your time