To position a window manually on the screen in Window Presentation Foundation you can use these system properties Window.Left and Window.Top. To get the size of the screen you can use these system properties:

System.Windows.SystemParameters.PrimaryScreenWidth;
System.Windows.SystemParameters.PrimaryScreenHeight;

To set a window (the green one) position like the one shown at the image below, you can use this method:

private void SetWindowPosition()
{
    Left = SystemParameters.PrimaryScreenWidth - (double)GetValue(WidthProperty) - 30; ;
    Top = 150;
}

Tags: wpf