 <p>In fact CoCreateGuid() calls <a href="http://msdn.microsoft.com/en-us/library/aa379205%28VS.85%29.aspx" rel="nofollow noreferrer">UuidCreate()</a>. The generated Data Types<a href="http://msdn.microsoft.com/en-us/library/aa379358%28VS.85%29.aspx" rel="nofollow noreferrer">(UUID,GUID)</a> are exactly the same. On Windows you can use both functions to create GUIDs</p>