A class identifier (CLSID) is a globally unique identifier that identifies a COM class object. If the server or container allows linking to embedded objects, register a CLSID for each supported class of objects.
The CLSID key contains information used by the default COM handler to return information about a class when it is in the running state.
To obtain a CLSID for your application, use UUIDGEN.EXE found in the \TOOLs directory of the COM Toolkit, or use CoCreateGuid.