go to Power Options, on the left select Choose what the pwer button does, disable Turn on Fast Startup, problem solved. this basically disables the HD swap function and causes the Windows 7 like shutdown always
Thanks - sorted an intermittent
problem on my upgraded win 8 desktop with a PS/2 Keyboard.
Came to it several times to find it switched on after it had been shut down properly the night before????
Mystery solved when our cat jumped off my knee onto the keyboard and the computer started to boot.
Applied your fix and our cat can no longer use the computer unsupervised.