WPF

Private Sub btnGo_Click(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs)

     Dim nextWindow As Window = CType(TryFindResource("Window3"), Window)
     If (nextWindow Is Nothing) Then
         nextWindow = New Window3
         nextWindow.Show()
     Else
         nextWindow.Show()
     End If

 End Sub

void Window1_Loaded(object sender, RoutedEventArgs e)
{
      SystemEvents.PowerModeChanged += new PowerModeChangedEventHandler(SystemEvents_PowerModeChanged);
}

private void SystemEvents_PowerModeChanged(object sender, PowerModeChangedEventArgs e)
{
      if (e.Mode == PowerModes.Suspend)
      {
            //DemoBtn.Visibility = Visibility.Visible;
      }
      else if (e.Mode == PowerModes.Resume)
      {
            DemoBtn.Visibility = Visibility.Visible;
      }
}