If you no longer want to provide a reason when you do things like performing a server restart:
(Shutdown Event Tracker)
Open the Group Policy Editor via RUN: gpedit.msc
Browse to the following: Computer Configuration -> Administrative Templates -> System.
Double-click: 'Display Shutdown Event Tracker'
Click 'Disabled', and then click OK.
Now close the Group Policy Editor. Restart the server or refresh the
GPO as follows: RUN -> gpupdate /force -> OK.
The change is effective immediately.