Sometimes, you may forget your password and can not login into ubuntu. You may want to retrieve password, however, it can not work in ubuntu system, you can only reset a new one. In this tutorial, we will introduce how to reset a forgotten password for users in order to make them can login into their system.
Reboot your pc and press shift key consistently
Press shift key consistenly, you may login into grub mode.
Select Advanced options for Ubuntu
Then you will find a recovery mode
Select a Ubuntu recovery mode and press enter
You will find a recovery menu, select root menu.
Then you can reset password for a user.
View all users
cat /etc/shadow
Select a user and use passwd command to change his password
If your username is zhilun, you can do like this:
passwd zhilun
However, if you encounter Authentication token manipulation error, you can read this tutorial to fix it.
Fix Ubuntu Passwd: Authentication token manipulation error – Linux Tutorial