The pen driver responds to the DRV_QUERYCONFIGURE message by reporting whether or not it provides a custom-configuration dialog box. The sample pen driver does provide a pen configuration dialog box by calling PENUI.DLL. The custom-configuration dialog box is implemented by the source code in the \PEN\SAMPLES\PENUI directory, which produces PENUI.DLL.
The driver responds to the DRV_CONFIGURE message by displaying the custom-configuration dialog box.