When the progress bar is enabled, a place-holding "box", the dimensions of the WebHtmlEditor, surrounds the progress bar. This property gets or sets the border width of that box.
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