If you plug in your Alfa USB device and see the message "USB Device Not Recognized", unplug it and restart your PC, and try it again in a different port. If it works, it was likely a one-time issue with the pins in your USB cable not making full connection with the USB port.If the problem continues, make sure the cable fits the computer and the Alfa adapter with a correct tight it. Then try a different USB cable if you happen to have another one laying around.USB Device Not Recognized error happening repeatedly is caused by a malfunctioning USB cable or Alfa USB adapter. If issue persists, contact your retailer for replacement or warranty options.