Thanks for the ideas Herman. My goal is to write/read from the USB device. Whatever it takes to get there is what I'll have to do. I was hoping to do something like the list below:

1. Call SetupDiGetClassDevs(interface_guid, 0, 0, DIGCF_PRESENT | DIGCF_DEVICEINTERFACE) to get a list of devices.
2. Call SetupDiEnumDeviceInterfaces() to get a list of available device interfaces.
Call SetupDiGetDeviceInterfaceDetail() to fetch information for the actual device interface we are going to use.
3. Use the DevicePath member of the PSP_DEVICE_INTERFACE_DETAIL_DATA structure returned by the SetupDiGetDeviceInterfaceDetail() call as the devicename/filename in the CreateFile() call.
4. Call WriteFile() repeatedly to send data to the device.
5. Call CloseHandle() to close the device

or:

Use SetupDiGetInterfaceDeviceDetail,
port number from original guid, get handle to it (passing
device name to createfile(), use closehandle to close device,
use deviceiocontrol() generate a CTL_CODE, make command packet,
send using deviceiocontrol() send TXPacket and read from RXPacket

The device is a mobile USB printer which includes a card swipe for drivers licenses. I can write/read from it via Bluetooth (when a virtual com port is created). I now need to do the same via USB. At first I was hoping it was a HID but its not so my only real choice (that I know of so far in my research) is using setupapi. By all appearances it should be possible...

Here is the link I was going by:
http://windowssdk.msdn.microsoft.com/en-us/library/ms681232.aspx




>>Thanks Herman, I sent you one more code example to test to verify this for me. I am seeing those same results you mention in WinXP. I can pull the data from the registry (where the GUID is irrelant using SetupDiGetDeviceRegistryProperty()) but not using SetupDiEnumDeviceInterfaces() in WinXP - only for HID Devices.
>>
>>I REALLY was hoping that was not the case :0(
>>
>
>Tracy,
>
>Yup, the results is the same.
>
>Well, I think this will be really hard :-(
>I read some more from Windows DDK, the GUID_DEVCLASS_xxx is not a DEVICE INTERFACE CLASS, but a DEVICE SETUP CLASS. I think you have to create your own device driver to expose the Device Interface (you must have a DDK for this). I never make a Driver to Interface, so that things is beyond my knowledge.
>
>One more thing, maybe you can try to create device interface by using SetupDiCreateDeviceInfoList(). For more info search for that function at MSDN.
>
>Just for my curiousity, are you really need SetupDiEnumDeviceInterfaces() to make it work?
>
>Good luck!