How to Disable second screen in Ubuntu

On update, ubuntu shows 2 screen as default.

Here is fix

xrandr | grep connected
sudo nano /etc/lightdm/
 xrandr --output HDMI1 --off #change HDMI1 with your device id ( you can check by executing command 'xrandr'
sudo chmod +x /etc/lightdm/

Edit /etc/lightdm/lightdm.conf and add the following line to the file


It will remove 2nd screen on OS starting.