After you install the Barr software, you must install the hardware key on a parallel port (LPT1, LPT2, or LPT3) or a USB port on your computer. Hardware keys that attach to parallel ports act as a pass-through to the printer or other peripherals so it does not prevent the port from being used for other purposes. If more than one device requires a parallel port, daisy chain the hardware keys together from the same port. For example, plug the hardware key into the parallel port, and then plug the printer into the hardware key. Hardware keys that attach to the USB port can be attached to a hub to allow other connections to the USB port. You may be required to restart your computer before the BARR/PRINT390 for IPDS software can be used.
After you install the Barr software and the hardware key, you can display the hardware key serial number by selecting About BARR/PRINT390 for IPDS from the BARR/PRINT390 for IPDS control icon.