Ubuntu 12.04 remove quest login from lightdm

LightDM ubuntu display manager

How to remove quest login from LightDM

open with an editor lightdm.conf

sudo gedit /etc/lightdm/lightdm.conf


add this row at the end

allow-guest=false

new lightdm.conf is now like that

[SeatDefaults]
greeter-session=unity-greeter
user-session=ubuntu
allow-guest=false restart LightDM
sudo service lightdm restart