Many icons typically have extra space around their central images, so the padding value is only necessary if additional space is necessary. Padding values can be positive or negative. Negative values cause the icon to overlap the edge of the control. The default icon padding is 0.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2