Many Linux distributions permit the use of the root user as a primary login, however, the dominant and popular Ubuntu has left some users in a conundrum. In order to perform tasks as a root user, this must be performed within a terminal window with the sudo command. However, here are a set of instructions that will allow the root user to login to an Ubuntu system.

Set the root password

• Go to System> Administration > Users and Groups.
• Select “root”.
• Click Unlock, enter the password for the account you are logged into as, and hit close.
• Click Properties, select “Set password by hand”, and set the root password.

Enable the root login

• Go to System> Administration> Login Window.
• Click Security tab.
• Check “Allow local administrator login”.
• Click on OK.
• Log out, then enter root for user name and the password you set in the first step and click Login.

There are many reasons as to why you shouldn’t login as root, however, that is not the point of this article.

I found this information here and have successfully tested in Ubuntu 8.1.0.