How are devices identified uniquely?

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

Here is the WMI code to detect the USB controllers/devices on your system. It was generated by Scriptomatic v2 from MS that you can download for free.

Note the results from my system is trimmed down to remove the controllers and I only left the device - my Sony digital camera. It specifies "REMOVABLEMEDIA" as a type. I didnt get my pen drive out for the test but I would think it would show as different. Maybe I'll try it now.

VB Code:

On Error Resume Next
 
Const wbemFlagReturnImmediately = &h10
Const wbemFlagForwardOnly = &h20
 
arrComputers = Array("VBGURU")
For Each strComputer In arrComputers
   WScript.Echo
   WScript.Echo "=========================================="
   WScript.Echo "Computer: " & strComputer
   WScript.Echo "=========================================="
 
   Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\CIMV2")
   Set colItems = objWMIService.ExecQuery("SELECT * FROM Win32_USBControllerDevice", "WQL", _
                                          wbemFlagReturnImmediately + wbemFlagForwardOnly)
 
   For Each objItem In colItems
      WScript.Echo "AccessState: " & objItem.AccessState
      WScript.Echo "Antecedent: " & objItem.Antecedent
      WScript.Echo "Dependent: " & objItem.Dependent
      WScript.Echo "NegotiatedDataWidth: " & objItem.NegotiatedDataWidth
      WScript.Echo "NegotiatedSpeed: " & objItem.NegotiatedSpeed
      WScript.Echo "NumberOfHardResets: " & objItem.NumberOfHardResets
      WScript.Echo "NumberOfSoftResets: " & objItem.NumberOfSoftResets
      WScript.Echo
   Next
Next

VB Code:

AccessState: 
Antecedent: \\VBGURU\root\cimv2:Win32_USBController.DeviceID="PCI\\VEN_8086&DEV_24D2&SUBSYS_80A61043&REV_02\\3&267A616A&0&E8"
Dependent: \\VBGURU\root\cimv2:Win32_PnPEntity.DeviceID="USBSTOR\\DISK&VEN_SONY&PROD_SONY_DSC&REV_4.50\\6&35C56897&0"
NegotiatedDataWidth: 
NegotiatedSpeed: 
NumberOfHardResets: 
NumberOfSoftResets: 
 
AccessState: 
Antecedent: \\VBGURU\root\cimv2:Win32_USBController.DeviceID="PCI\\VEN_8086&DEV_24D2&SUBSYS_80A61043&REV_02\\3&267A616A&0&E8"
Dependent: \\VBGURU\root\cimv2:Win32_PnPEntity.DeviceID="STORAGE\\REMOVABLEMEDIA\\7&5D1629E&0&RM"
NegotiatedDataWidth: 
NegotiatedSpeed: 
NumberOfHardResets: 
NumberOfSoftResets:

Ok here it is for my jump drive or pen drive. There is an identifier between the 2.

VB Code:

AccessState: 
Antecedent: \\VBGURU28\root\cimv2:Win32_USBController.DeviceID="PCI\\VEN_8086&DEV_24DD&SUBSYS_80A61043&REV_02\\3&267A616A&0&EF"
Dependent: \\VBGURU28\root\cimv2:Win32_PnPEntity.DeviceID="USBSTOR\\DISK&VEN_&PROD_USB_DISK_PRO&REV_1.13\\483619010A5B&0"
NegotiatedDataWidth: 
NegotiatedSpeed: 
NumberOfHardResets: 
NumberOfSoftResets: 
 
AccessState: 
Antecedent: \\VBGURU\root\cimv2:Win32_USBController.DeviceID="PCI\\VEN_8086&DEV_24DD&SUBSYS_80A61043&REV_02\\3&267A616A&0&EF"
Dependent: \\VBGURU\root\cimv2:Win32_PnPEntity.DeviceID="STORAGE\\REMOVABLEMEDIA\\7&D5604D5&0&RM"
NegotiatedDataWidth: 
NegotiatedSpeed: 
NumberOfHardResets: 
NumberOfSoftResets:

I am sorry, but i donot understand what is happening???
I would be gr8ful if u could explain me what is going on???
Why do u need an array in the first place?
By the way which property is giving u removable media???

Thank you