public static extern int DwmExtendFrameIntoClientArea(IntPtr hWnd, ref MARGINS pMargins);
private void Window_Loaded(object sender, RoutedEventArgs e) { if (Environment.OSVersion.Version.Major >= 6 && DwmIsCompositionEnabled()) { // Get the current window handle IntPtr mainWindowPtr = new WindowInteropHelper(this).Handle; HwndSource mainWindowSrc = HwndSource.FromHwnd(mainWindowPtr); mainWindowSrc.CompositionTarget.BackgroundColor = Colors.Transparent; this.Background = Brushes.Transparent; // Set the proper margins for the extended glass part MARGINS margins = new MARGINS(); margins.cxLeftWidth = -1; margins.cxRightWidth = -1; margins.cyTopHeight = -1; margins.cyBottomHeight = -1; int result = DwmExtendFrameIntoClientArea(mainWindowSrc.Handle, ref margins); if (result < 0) { MessageBox.Show("An error occured while extending the glass unit."); } } addNewTab(); //webBrowser1.LoadURL("http://google.co.uk"); }