Hi, ELD123 I personally faced this too , what i did was looked up for every option available for this but there are options only available to change , delete not to add a new one , so what i did was that i cleared all the data like :- cache , cookies , forms etc. So as to get it as brand new , and then i visited that same website where i wished to login and that pop-up which you mentioned came in and i opted yes. Other trick is , enter anyone else id and password which works for that different id it will ask again then opt to remember it then go to login settings , there you can edit them and enter your's one there. I hope it helps. Have a happy browsing with Mozilla, Regards:- gaurav1999