Sven Groot said:

Nevermind, didn't read the question properly.

Since I had the problem, the KB article now appears to have been corrected and the solution now works.

 

The previous article showed a registry name of SetHibernateDefault = 1 instead of ShowHibernateButton = 1

in the registry path.  Another error in the KB article was the omission of "Policies" in the registry path

and therefore the value could not be found.

 

The current article appers to have been corrected - and now works showing all shutdown buttons.