I've had this problem before where the dual monitor setup would not be kept (i.e. I had my right screen as the main screen, but after restarting, the position of my right screen would be shifted to the left.), did a fresh reinstall and the problem got fixed (probably some other DE configs overriding each other since I had KDE, Gnome and Unity).

However, the problem now is that the dual monitor setup would be still broken on the login screen (my right screen would become the left one) and the screen config would only be fixed after I had logged in.

  • Do you know if you're using lightdm or some other display manager? Oct 7, 2016 at 1:13
  • @Zacharee1 I'm definitely using lightdm, however there's no lightdm.conf file, only lightdm-gtk-greeter.conf and users.conf with a empty lightdm.conf.d folder.
    – dll
    Oct 7, 2016 at 1:17
  • what about askubuntu.com/questions/360886/… Oct 7, 2016 at 1:20
  • @Zacharee1 Tried that, didn't fix the problem.
    – dll
    Oct 7, 2016 at 12:49
  • no effect at all? Oct 7, 2016 at 14:08

1 Answer 1


Install arandr by pasting the following in terminal:

sudo apt install arandr

Open arandr. Your screens are probably configured how you like. If so, go to Layout > Save As. Open the saved script and copy the entire xrandr command.

Create the file /etc/lightdm/lightdm.conf if it is not created already. You can use:

sudo mousepad /etc/lightdm/lightdm.conf

Now paste the following. Replace my xrandr command below with your own.

display-setup-script=xrandr --output VGA-0 --mode 1440x900 --pos 0x72 --rotate normal --output DVI-0 --mode 1440x900 --pos 3360x82 --rotate normal --output HDMI-0 --mode 1920x1080 --pos 1440x0 --rotate normal

Reboot and your login screens should be correct.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .