I had the same problem with my redfury when I got that, I got it working by using the program "Zadig" to force it to use the winusb driver as windows automatically assigned a driver from online which was the wrong one and bfgminer wouldnt find it.
If you're using zdiag for bfgminer, you're doing it wrong. You only need zdiag for cgminer, because cgminer uses their own retarded drivers.