For a long time, Windows CE developers and users have wanted to disable the USB Driver Dialog that is displayed when an unknown USB device is plugged into the host controller.   Of course the question is always why would you want to do such a thing? The simple answer is that there are USB devices that are needed, like printers, which expose multiple functions to the bus, like scanners and faxes, which no Windows CE driver exists to support.   So the printer quietly loads a driver, but then the other functions cause a dialog to be shown.

One solution is to create a USB Class driver that loads by default if no other driver has been loaded. This driver just accepts anything that it sees and then does nothing with it.

Starting with the Windows Embedded CE 6.0 R3 March QFE/update, the USB 2.0 driver has a registry value to disable the dialog:

 

Setting the DoNotPromptUser value to 1 disables the dialog. The default value is zero, so the driver continues to behave in the same way it always did unless you change this registry value.