A Plug and Play device was removed or became available again.
(IUnknown*) Pointer to the IUnknown interface of the filter that represents the device.
Zero if the device was removed, or 1 if the device is available again.
When the device becomes available again, the previous state of the device filter is no longer valid. The application must rebuild the graph in order to use the device.
Build date: 11/16/2013