I have been searching the web for about a week now trying to figure this one out, I even messaged the HP people and they gave me a none helpful answer. I am a tech for the Army I have recieved a HP 9100c digital sender from a different unit that has put an admin password on it but no one seems to remember what it is. I need to do a manual reset on it which I know is possible but can't remember how to do it.