The subkeys and registry values associated with the HKEY_LOCAL_MACHINE\SOFTWARE\Classes key contain information about an application that is needed to support COM functionality. This information includes such topics as supported data formats, compatibility information, programmatic identifiers, DCOM, and controls.
|AppID||Configuration options for COM-based applications.|
|CLSID||Configuration options for COM classes.|
|<file_extension>||Associates a file name extension with a ProgID.|
|FileType||Used by GetClassFile to match patterns against various file bytes in a non-compound file.|
|Interface||Associates an interface name with an interface ID (IID).|
|<ProgID>||Identifies a class. Note that the ProgID is not guaranteed to be globally unique, unlike a CLSID.|
|<version-independent ProgID>||Used to determine the latest version of an object application.|