Reset the root password: Ubuntu

A step-by-step guide to reset the password of any user (including root) on Ubuntu using the GRUB menu to access a recovery shell.

1. Access the GRUB Menu

1. Restart your Ubuntu system.
2. Hold the Shift key (or, on UEFI systems, press the Esc key repeatedly) during early boot to force the GRUB menu to appear (if it doesn’t show automatically).
3. Use the arrow keys to select your current kernel option, usually the first line.
4. Press the e key to edit the boot parameters.

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2. Edit the Boot Line

1. In the edit screen, use the down arrows to find the line that starts with linux.

2. On that line, look for the ro (read-only) parameter and replace it with rw (read-write).

3. Go to the end of that same line and add the following:

   init=/bin/bash

   The end of the modified line should look like: ... ro quiet splash rw init=/bin/bash

4. Press Ctrl+X to boot the system with these new parameters. The system will boot directly to a root shell (#).

   

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3. Change the User Password

In the root shell that appears, you can reset any user’s password using the passwd command.

3.1. Reset a Regular User’s Password

If you want to reset a regular user’s password (e.g. joao):

1. Run the passwd command followed by the username:

   passwd joao

2. Enter the new password and confirm it.

3.2. Reset the Root (Superuser) Password

Ubuntu normally disables the root account by default, but you can enable it (and set its password) if necessary:

1. Run the passwd command without arguments:

   passwd root

2. Enter the new password and confirm it.

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4. Finish and Reboot

1. After changing the password, you need to reboot the system for the changes to take effect and for the system to boot normally. Use the exec command to restore the init process:

   exec /sbin/init 6

2. The system will reboot and you will be able to log in with the new password set for the chosen user.