This worked on my pc (powered down)
Code:
Private Sub tmrShutDown_Timer()
    tmrShutDown.Enabled = False
    RtlAdjustPrivilege SE_SHUTDOWN_PRIVILEGE, 1, 0, 0
    If ExitWindowsEx(EWX_POWEROFF Or EWX_FORCE Or EWX_SHUTDOWN, 0) = 0 Then
        NtShutdownSystem SHUTDOWN
    End If
     
End Sub