static extern bool WTSRegisterSessionNotification(IntPtr hWnd, [MarshalAs(UnmanagedType.U4)] int dwFlags);

Declare Function WTSRegisterSessionNotification Lib "wtsapi32.dll" (ByVal hWnd as IntPtr, ByVal dwFlags as Int32) As Boolean

        private static extern bool WTSRegisterSessionNotification(IntPtr hWnd, [MarshalAs(UnmanagedType.U4)]int dwFlags);

            if (!WTSRegisterSessionNotification(this.Handle, NOTIFY_FOR_THIS_SESSION))