I have a old version of EI version 4 that came with the modeler. I upgraded my PC installed a Parallel PCI Adapter card, Then Installed EI and the sentinel drivers, but I am getting the "Hardware Key Error: DRIVER_NOT_INSTALLED" the PCI card supports SPP/EPP/ECP serial ports ( I'm on a PC win8.1} I really need the modeler! Any help will be welcome. Thanks