Essam, Try to put the car in sleep mode for three or four hours (that is to disconnect the battery completley and then reconnect the battery with the GPS drive connected). This might force the OBC to find the GPS computer as a device on the car, if the nav computer is NOT faulty, you will get a line on your screen next to Telivision and Aux Vent saying (Navigation GPS) or (Onboard Navigation), if you click it and the nav is working you will see a blank screen with one message in the left upper corner stating (No CD/DVD in device) that is all. try to get the CD/DVD for your location and good luck.