[PatK]

I suppose you could delete C:\Users\Your_Computer_Name\AppData\Roaming\Kodi\userdata\guisettings.xml and it will return to default settings next launch. Or if you have that file in a back-up somewhere, inject it over top the existing file. Alternatively you could try changing this line: <setting id="Hide_Shutdown_Shutdown" type="bool">false</setting> in the C:\Users\Your_Computer_Name\AppData\Roaming\Kodi\userdata\addon_data\skin.transparency\settings.xml