To enter the graphics mode in Ubuntu as root, you must do the following:
If you have not yet set a password for the root user should do so now by typing in a terminal and running:
$ sudo passwd root
The system asks for the password you entered in the installation, then you must enter the new root password and confirm.
Now you must use the command in the terminal and enter your root password.
In GNOME you go to the menu System -> Administration -> login window. On the Security tab, mark Enable root user can log in and accept GDM.
KDE is a bit more cumbersome. If you use KDM, open up the folder /etc/kde3/kdm. When you reach the file or folder search file kdmrc. Click the right mouse button on kdmrc ,and select “Edit as root“. Look for the line that say AllowRootLogin = false and change false to true. Save changes and quit.