If for some reason you lose your root password you can change it by following these steps:
- Reboot your machine.
- From GNOME, log out, and choose the reboot option. Or from the login screen, click 'System' then 'Reboot'. From console mode, press Ctrl-Atl-Del (which in Linux reboots the system in a controlled fashion). You will see the shutdown sequence begin.
- Allow the system to reboot to the GRUB splash screen, and then press "e". Select the line containing "kernel", and press "e" again. GRUB will display the line in edit mode.
- Add "single" to the end of the line, and press return. GRUB will return you to the previous screen.
- Press "b" to boot the system into what will now be single user mode. The system will come part of the way up, and then drop you into a root shell - the prompt will look like this:
sh-2.05# _ - Type "passwd" and press return. The system will ask you for a new password. Type in your new password, then to retype it as confirmation (it will not display on the screen). If the two entries do not match, it will ask you to try again. It will also warn you if it thinks the password is too obvious; you can ignore the warning, but if you are on a computer that either isn't behind a firewall or is in a public area, this is not recommended.
- Once the new password is in place, type "exit" and press return to allow the system to finish booting.