This function frees all the DLLs that have been loaded with the CoLoadLibrary function (called internally by CoGetClassObject), regardless of whether they are currently in use. This function is usually not called directly, because CoUninitialize calls it internally.
To unload libraries, CoFreeAllLibraries uses a list of loaded DLLs for each process that the COM library maintains. The CoUninitialize function calls CoFreeAllLibraries internally, so OLE applications usually have no need to call this function directly.
To determine whether the platform supports this function, see Determining Supported COM APIs.