I have several of the above handsets but can't register any of them on the replacement, identical base that I had to buy when the original one was zapped by lightning. To register, I need to navigate to the 'ADVANCED SETTINGS' option on the menu but can only get the 'SETTINGS' screen which is preceded by the 'Calling Features' option and followed by the 'Do not disturb' option. There's no sign of the 'ADVANCED SETTINGS' screen - so I'm stuck!