Metric types distinguish different metric capture libraries from each other, ensuring that we can correctly correlate the same metric between sessions and not require category names to be globally unique. If you are creating a new metric, pick your own metric type that will uniquely identify your library or namespace.
Requirements
Target Platforms: 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