Recently I noticed a problem with Windows 8, in some cases it didn't shut-downed properly and the screen kept displaying "shutting down" and the wait and wait, the same during the shutdown step of Windows 8 Restart. The only option that the user have in this case is the Hard Off, which in not safe in many aspects.
Well, I inspected these keenly, and the only thing that i can find common was the current "Avast Antivirus", and fortunately removing the Avast antivirus cured this issue, for my friends, and for both of my systems.
So, if you too are facing the same problem, try removing avast from your system, and check the results, may be this this helps to repair your windows 8 shutdown / restart problem.
If you are unable to remove avast from your system due to some errors, you can use avast removal utility.
Download it from Here!