How to return the login screen of the original unity ubuntu?

Question

I've installed the LightDM GTK+ Greeter 1.7.0 as below

sudo add-apt-repository ppa:lightdm-gtk-greeter-team/stable
sudo apt-get update
sudo apt-get install lightdm-gtk-greeter

(http://www.smdavis.us/2013/12/28/lightdm-gtk-greeter-1-7-0-released/?utm_source=rss&utm_medium=rss&utm_campaign=lightdm-gtk-greeter-1-7-0-released&utm_reader=feedly)

Now I want to return to the original login screen of unity ubuntu. Please show me a way. Tasks done but have no result:

sudo ppa-purge ppa:lightdm-gtk-greeter-team/stable.
sudo apt-fast remove lightdm-gtk-greeter
sudo apt-fast install --reinstall lightdm.

Solution 1

First purge the package and remove the PPA.

sudo apt-get purge lightdm-gtk-greeter*
sudo add-apt-repository --remove ppa:lightdm-gtk-greeter-team/stable
sudo apt-get update 

Then edit the file that reads the greeter.

gksudo gedit /etc/lightdm/lightdm.conf.d/10-ubuntu.conf 

change this line greeter-session=lightdm-gtk-greeter to this greeter-session=unity-greeter

if the line above does not exist, add it.

if above file/path does not exits (depends on Ubuntu version) try this one

gksudo gedit /etc/lightdm/lightdm.conf 

Then reconfigure both DM and greeter

sudo dpkg-reconfigure lightdm unity-greeter

Reboot your PC.

Solution 2

Edit your /etc/lightdm/lightdm.conf file, and make sure that the greeter-session is set to unity-greeter, so there has to be a line like the following:

greeter-session=unity-greeter

Comments

[evergreen]

My platform Ubuntu 13.10: apply to gksudo gedit /etc/lightdm/lightdm.conf. Quite success.

[Hitechcomputergeek]

On my Ubuntu 15.04, there was only one file in /etc/lightdm, /etc/lightdm/users.conf. So instead I just did sudo apt-get purge lightdm-gtk-greeter (it had installed it from the official repos so I didn't actually have to remove any PPAs), then did sudo dpkg-reconfigure lightdm unity-greeter. After that, it worked. I actually think that you may not even have to do the dpkg-reconfigure step, but I haven't tested this.

[Nonny Moose]

This answer is best for any users who do not wish to uninstall any packages.