This option allows you to stop users from being able to shutdown the computer by disabling the shut down command.

Open your registry and find the key below.

Create a new DWORD value, or modify the existing value called 'NoClose' using the settings below.

Exit your registry, you may need to restart or log out of Windows for the change to take effect.

Settings:
User Key: [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\
Explorer]
System Key: [HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\
Explorer]
Name: NoClose
Type: REG_DWORD (DWORD Value)
Value: (0 = shutdown enabled, 1 = shutdown disabled