Unregisters an event handler (callback function) that was previously registered using the PrlVm_RegEventHandler function.
PRL_RESULT PrlVm_UnregEventHandler( PRL_HANDLE hObj, PRL_EVENT_HANDLER_PTR handler, PRL_VOID_PTR userData );
PrlApiVm.h
PRL_RESULT. Possible values:
PRL_ERR_INVALID_ARG - invalid handle or null pointer was passed.
PRL_ERR_SUCCESS - function completed successfully.
Use this function when you no longer want to receive event notifications from the virtual machine. The values of the handler and userData parameter constitute a unique pair which will be used to identify the event handler that will be unregistered. Make sure that you supply the same values as the ones you used when you registered the handler.