Here is what I could see with Windows XP and a custom WCID device. It is possible to have a generic INF-file with USB\MS_COMP_WINUSB instead of VID-PID pair. XP recognizes a WCID device and accepts this kind of INF that installs WinUSB as the functional driver. See the ZIP attached. I did not include heavy DLL files. You will need to replace them with real binaries from the latest WDK. It seems it is the only advantage WCID have with XP, i.e. the generic INF. XP will ask for the driver once again if another WCID device is found, i.e. VID/PID is different. Otherwise, WinUSB seems to work fine for this kind of driver installation.
post edited by Bambur - 2012/03/01 08:19:19