If you want to load Usbser.sys automatically, set the class code to 02 and subclass code to 02 in the Device Descriptor.
The driver is loaded based on a compatible ID match similar to other USB device class drivers included in Windows. If your device belongs to the Communications and CDC Control device class, Usbser.sys is loaded automatically.You do not need to write your own INF to reference the driver. In Windows 10, a new INF, Usbser.inf, has been added to %Systemroot%\Inf that loads Usbser.sys as the function device object (FDO) in the device stack. For the list of USB device class driver included in Windows, see USB device class drivers included in Windows. If they are not installed automatically, contact the device manufacturer. If you trying to install a USB device class driver included in Windows, you do not need to download the driver.
