I answer my own questions for the sake of the archive because maybe somebody else in the world is as stupid as I am. :) Regards to all. Exposing custom properties from PortCls-based miniports is trivially easy *once you already know how to do it*. > Q. Will I be able to access user-defined properties (not DRIVER_SPECIFIC > but with new GUID's) or will ksproxy hide them from me? Yes. PortClass will expose any property you want to define. Read about Streaming properties to get the structures right (contains a KSPROPERTY as the first member, etc). This is neat! I don't know why there aren't more enthusiastic exclamation points in the documentation. > Problem: how to open the driver from the control panel while a WDM-KS > program has exclusive access. Again, "Hmmm." Perhaps the topology is not > locked? Or do I need to expose another driver object, etc, etc? You (or should that be "I") can instantiate the stream to set properties on it without instantiating the pins, so if you put your custom properties as stream properties (rather than nodes) you can manipulate the stream while it's open and running. t/DD -- Tom Surace <tekhedd@xxxxxxxxxxxxxx> BYTE HEAVEN <http://www.byteheaven.com/> ****************** WDMAUDIODEV addresses: Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx Subscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe Unsubscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe Moderator: mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx URL to WDMAUDIODEV page: http://www.wdmaudiodev.de/