I frequently upgrade the desktop of my daughter (using ubuntu 12.04.1) through the official processes,but in the latest attempt the computer is asking for a root (or super user) password. In the past I always used the administrator password. This one is now no longer accepted. Can't also not unlock the administrators account in
users accounts. Every that used the computer claims not to have entered a root password. Nobody knows another password than the administrator password? Something must have gone wrong somewhere.
How do I disable the root password? I have tried some advices from this site, such as
sudo passwd -dl root, but the computer replies that
the administrator is not in the sudoers file after entering the administrators password.
What can I do to remove or get around the root password?