SerialPortPropPageProvider Tab for UMDF Driver not showing up

Question

I have written a virtual serial driver in UMDF.
Now I am trying to add the standard port settings tab to the device manager dialog by adding HKR,,EnumPropPages32,,"msports.dll,SerialPortPropPageProvider"
to my inf file in the AddReg section.
However, the tab does not show up.

What am I missing?

Thanks in advance
Alex

Answer 1

The expand further...the PortSubClass value is needed since the class installer tries to dynamically add the property page at runtime. Since the ports class contains both serial and parallel ports, the PortSubClass value tells the class installer what type of port it is (1 being a serial port). The EnumPropPages32 value that you used in the INF explicitly adds the property page (the PortSubClass check is essentially skipped). Technically you should always include the PortSubClass value in the INF, even if you are also explicitly adding the EnumPropPages32 value, as there are other edge conditions in the OS that read this value and make decisions based on the result.