Login to your computer with your personal account. Open a terminal and type the following: You should see the following:
Move the cursor to a new line at the end and enter the following line:
Press “Ctrl +o” to save the changes and “Ctrl + x” to exit.
Restart Lightdm. Alternatively, you can restart the computer. On the next login, the “Guest Session” mode will no longer show up in the login option.
More Configuration
If you want to disable the “remote login” option as well, add the following line to the lightdm.conf file.
Don’t forget to restart Lightdm
Restoration
To restore the login screen to the default state, simply undo the changes you have made. That means, remove the line “allow-guest=false” or “greeter-show-remote-login=false” from the lightdm.conf file.
