Unregisters an existing overlay icon.
bool UnregisterIcon(const QString& qsProductGUID, const QString& qsIconId);
This method unregisters the overlay icon identified by IconId. If the system must be rebooted to completely remove the icon, this method returns true, otherwise it returns false.
The same values must be passed for the ProductGUID and IconId parameters as were passed when RegisterIcon was called; please refer to its documentation, as well as the Custom Drive Icons topic, for more information.
This method is available in both the class API and the Installer DLL included with the product; please refer to the Windows Driver Installation topic for more information about the latter. The Helper DLL must be installed in order for this method to function correctly. Applications can check to see whether the Helper DLL is installed using the GetModuleVersion method, and install it using the Install method if necessary.
This method requires administrative rights to execute successfully. If the user account of the process that calls this method doesn't have such rights, the call will fail with an ERROR_PRIVILEGE_NOT_HELD (0x0522) error.
Note: This method cannot be called within events.
This method returns a Boolean value; after it returns, call the GetLastErrorCode() method to obtain its result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message.