How do I disable auto login in ubuntu



when you  get  some  issues  that  your Ubuntu cannot  start normally   but autologin still activated ,  (Gnome  Freezing) ?


1.Press, ctrl+alt+F1 to   get the  terminal
2. Log in
3. sudo vi /etc/gdm/custom.conf
4. changed AutomaticLoginEnable to false (you’ll have to press ‘i’ for insert)
5. save (Esc -> :wq)
6. sudo reboot

You’ll see login screen now!