CoUninitialize

Closes the OLE Component Object Model(COM) library, freeing any resources that it maintains and forcing all RPC connections to close.

oid CoUninitialize();

Comments
The CoInitialize and CoUninitialize calls must be balanced

if there are multiple calls to the CoInitialize function, there must be the same number of calls to CoUninitialize: Only the CoUninitialize call corresponding to the CoInitialize call that initialized the library can close it.

The OleUninitialize function calls CoUninitialize internally, so applications that call OleUninitialize do not also need to call CoUninitialize.

The CoUninitialize function should be called on application shutdown, as the last call made to the COM library after the application hides its main windows and falls through its main message loop. If there are open conversations remaining, CoUninitialize starts a modal message loop and dispatches any pending messages from the containers or server for this OLE application. By dispatching the messages, CoUninitialize ensures that the application does not quit before receiving all of its pending messages. Non-OLE messages are discarded.