I have only had this problem recently, when I attempt to restart the computer from windows, it shuts down completely instead of restarting? i have searched online and cant seem to find any one else with this issue, I am running windows 8.1
Did this just start with Win8.1? Some MB's will go through a complete shut down first and moments later re-start. Have you wauted a few seconds to see if it tried to start back up?
I just built the pc a few weeks ago and installed windows 8.1, i have not wiated to see if it restarts but im almost positive it does not, i will check to see if this is the problem