In Ubuntu Linux operating systems, the root account is blocked and cannot be used by users who do not have 'superuser' rights. To enable the root privileges on a user's account, sudo or gksu commands can be used. The
sudo command in Linux allows users to set up the password mode for the root users in order to activate the console sessions in command mode only. The graphical user interface cannot be accessed with the
sudo commands. To enable the root privileges on a graphical user interface, the login and security settings have to be changed through the administration tools.
Here the Solution to access the Administrator is:
To enable the root account and access directly via the console in root mode, you must type the command:
sudo passwd root
This command allows you to set up the password mode for the root user which will be activated for the console sessions only (no GUI). Once the password is initialized, it will be possible to open a console session with the user root.
To enable access to the graphical user root, go to System/Administration/Login, click the Security tab, then tick the box allowing connection of the local System Administrator.
Disconnect and reconnect with the root account.