How do I reset a lost administrative password? - Ask Ubuntu

i'm working on ubuntu system, , client has forgotten administrative password. doesn't remember entering one; there.

i've tried suggestions on website, , have been unsuccessful in deleting password can download applets required running files. there solution?

by default first user's account administrative account, if ui prompting password it's person's user password. if user doesn't remember password need reset it. need boot recovery mode.

boot machine, , after bios screen, hold down left shift key. prompted menu looks this:

i've noticed on systems timing when hit left shift key can tricky, miss , need try again.

hit down arrow until select 2nd entry top (the 1 recovery mode in description) , hit enter.

now should see menu:

using arrow keys scroll down root , hit enter.

you should see root prompt, this:

root@ubuntu:~# 

at stage should have read-only filesystem. have remount write permissions:

mount -o rw,remount / 

now can set user's password passwd command. (in example use jorge example, need substitute whatever user's username is):

root@ubuntu:~# passwd jorge enter new unix password: retype new unix password: passwd: password updated root@ubuntu:~# 

type in want new password @ prompt. after it's successful reboot machine , user able log in new password.

• recovery mode documentation
• lost password documentation

---

there concern being security vulnerability. it not. need have physical access machine this. if has physical access pc, far worse change password. when comes physical access, battle security lost. wary of let on pc.

even setting root password not successful, 1 can boot init being /bin/sh , have full root access. again, given physical access, computer knowledge can computer.