This value represents the width (for left and right) or height (for top and bottom) of the title. It includes both the size of any lines of text in the title, as well as margin space.
The Extent value is specified in pixels.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2