If the name stays the same and you only need to change (update) the stored password then fill the name in the login form and let Firefox fill the wrong password.<br /> You may have to press the Tab key to fill the password field.<br /> If you replace the wrong password with the new password then Firefox should offer to store the new password.<br /> Use the Remember Password bookmarklet on websites that use "autocomplete=off" to prevent Firefox from saving passwords.<br /> You can verify that Firefox has stored the new password: Tools > Options > Security: Passwords: "Saved Passwords" > "Show Passwords"<br /> If that didn't work then remove that name and password in the Password Manager and Firefox should offer to save the new password on the next visit or after reloading the login page.<br /> If you have problems to remember a new password then make sure that you remove all entries from that server (look for an empty name as well) and also check the exceptions to make sure that the site is not listed there. See also: * http://kb.mozillazine.org/Password_Manager * http://kb.mozillazine.org/User_name_and_password_not_remembered (bookmarklet)