How to disable automatic login in LightDM?
gksudo gedit /etc/lightdm/lightdm.conf
It displays some text as follows:
[SeatDefaults]
greeter-session=unity-greeter
user-session=ubuntu
autologin-user=username
Solution
- This
<username>
would be your particular user name that is automatically logged in with or without password. Delete this username and type in the administrative username or leave it blank. - Shut down the system. It will go back to the login selection screen. Just power down the system and put it on again.
I had the same problem and it was solved by the command:
sudo gpasswd -d USER nopasswdlogin
where you should change USER by your user name.
System Setings
Disable Automatic Login