This is a quick tutorial that shows you how to remove the Guest session and the white dots from Unity’s login screen in Ubuntu 14.10 Utopic.
1. To remove the Guest session:
Press Ctrl+Alt+T on keyboard to open the terminal. When it opens, paste the command below and hit enter:
sudo gedit /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf
Type in your user password when it asks. Note that there’s no visual feed back when typing password.
As the picture shows, when the editor opens, add a new line into the end and save the file
That’s it. You won’t see the Guest next time Ubuntu boots up.
2. To Remove white dots:
There is a graphical tool dconf-editor which provides options to change the login screen background and remove the white dots (draw grid).
a.) To install dconf-editor, click the link below to bring up Ubuntu Software Center and click the install button:
b.) To configure Unity login screen, you need the lightdm user privilege to launcher dconf-editor. To do so:
Press Ctrl+Alt+T to open terminal. When it opens, run commands to get root privilege:
Type in your user password when it asks.
Allow user lightdm to create a connection to the X server:
Switch to user lightdm in this terminal window:
su lightdm -s /bin/bash
Finally start dconf-editor:
c.) When the dconf-editor opens, navigate to com –> canonical –> unity-greeter in left. Then disable the value for both draw-grid and draw-user-backgrounds.
Done. You’ll see the changes in next boot.