I have noticed at times, after having totally shut down my Alienware 17 R4, disconnected from the power supply and left it alone, that it had in some ways restarted itself: I hear its fan and see that it supplies power to the external fan it is connected to.

It also happens that when I pick it up (it being apparently totally off), it then starts.

Why does it happen, how can I prevent this? It just uses the battery for no good use.