Since Windows CE
is used for customized devices and some requirements demanded from the
customers to restrict certain USB devices based on the Vendor ID (VID)
or Product ID(PID). Device has to respond only to their USB accessories,
for example, Customer has designed their own USB HID device accessories
for their devices and expected to respond only for their accessories.
Even with their accessories they are introducing special featured
accessories and expecting the device (application) to act accordingly
for each accessory dynamically. So we need to take some decision on the
application which requires some unique ID(VID/PID) to identify the
connected accessory. Please see the below link to know more...
http://www.e-consystems.com/blog/windowsce/?p=878
http://www.e-consystems.com/blog/windowsce/?p=878