How to reset lost Ubuntu password using Terminal commands. Reset lost Root password in Linux Ubuntu 14.04 and other Ubuntu Derivatives. Recover and change forgotten password in Ubuntu 14.04 system. Follow the steps given below to reset Root password:
1. Boot your Ubuntu PC and enter into Boot Option. Press ESC key when you see the BIOS screen. On the GNU GRUB menu, select *Advanced options for Ubuntu.
2. On next screen, select select appropriate recovery mode and press Enter.
3. In the recovery menu, select ‘root – Drop to root shell prompt’ option.
4. Remount the filesystem to have write permission onto it. To do su, run the following command in the Terminal:
mount -rw -o remount /
Once the shell is remounted with read/write permission, you can change the password. Run the following command to change the password (as the root user).
sudo passwd username
Please note that you must replace username with your account name or user name for your Ubuntu system. You will be asked to create and confirm a password.
When you’re done entering a new password, restart the system to reset the password.