Friends

I am working on a project which requires detection of USB devices.
For this i am using WMI and using the class Win32_USBHub.
This class returns many properties like Device_ID, DESCRIPTION, Name etc.

but i would like to know how windows actually identifies a device.

For eg :- pen drive, keyboards, mouse, digital cameras etc.

Description for Pen Drive and Digital Camera gives "Mass storage device" .
So i cannot use Description property

Problem with Device_ID is every pen drive has got different Device_ID.
I want something that will uniquley address a pen drive device irrespective of their device_id.

Please help...
(Note:- solution in WMI is preferable)

THANK YOU