Change your forgotten password

This is Ubuntu/Debian specific and might differ in other Linux distributions.

So, you come back after a long vacation and don't remember your password ? Just change the password!

1. Reboot the system and Press Esc to enter the GRUB menu
2. Choose the menu option in which you see the "recovery" option of the latest kernel
3. Let your system boot and you will see a root shell soon
4. Change your password ! using passwd
5. You are done! Reboot and use your new password!