Have you had the personal identification number set? Or are you setting the router up for the first time . If the router has lost the ability to recognize the access number then unplug the router and hold the power button for about 30 seconds release the power button ,then plug the router in and boot it up. If this gives no joy then push the reset button on the back and set up your network again like you did the first time you set it up ,making new pin numbers and passwords. Hope this helps