Re: Power/shutdown does not turn computer off
Try shutting down, and immediately after failure open the Event Viewer (Click on Start, and start typing "Event Viewer" and it will be the desktop application shown at the top.)
In the Event Viewer, go to Windows Logs -> System. It may take a few minutes for it to be populated. Be patient, and wait for it to display.
Now, search through the log for any warning or error that may be stating a reason that it could not be shut down. It could be that you have a 3rd party program preventing shut down, or even malware can prevent shut down. This should show you what type of error is causing it.
Keep it sorted by date and time, and do a search (Ctrl+F for find) for "Winlogin". The first found entry should be your logging back into Windows. Now click "Find Next" and you should be brought to the last time you were logged out just before the attempted shutdown. This will help you to locate it a bit faster. Look at the entries above this where everything is shutting down, and see if you can find the warning or error that may be causing the issue.
Let us know what you find. Hopefully, this will help to resolve it.