Option Explicit
Const EWX_LOGOFF = 0
Const EWX_SHUTDOWN = 1
Const EWX_REBOOT = 2
Const EWX_FORCE = 4
Private Declare Function ExitWindowsEx Lib "user32" (ByVal uFlags As Long, ByVal dwReserved As Long) As Long
Private Sub Form_Load()
Dim msg As Integer
Dim ret As Long
      msg = MsgBox("This program is going to reboot your computer. Press OK to continue or Cancel to stop." _
            , vbCritical + vbOKCancel + 256, App.Title)
      If msg = vbCancel Then End
      ret& = ExitWindowsEx(EWX_FORCE Or EWX_REBOOT, 0)
End Sub