Restore Unity Greeter

I've installed XFCE Desktop environment, but when I decide to switch back to Unity, while uninstalling the XFCE packages, the LightDM keep starts like XFCE, and I want to restore the Unity one. I think that is called Unity Greeter. Can someone help me?

Solution 1:

I installed xubuntu-desktop on top of normal Ubuntu 14.04. Then I also noticed that the greeter had changed. I still use the xubuntu desktop, but I changed the greeter back by adding a line

greeter-session=unity-greeter

into /etc/lightdm/lightdm.conf.d/10-xubuntu.conf.

Update: Now on a new install of Ubuntu 14.10 + xubuntu-desktop on top of that, there is no directory lightdm.conf.d under /etc/lightdm. But following advice from here I created the directory /etc/lightdm/lightdm.conf.d and a file /etc/lightdm/lightdm.conf.d/50-myconfig.conf with contents

[SeatDefaults]
greeter-session=unity-greeter

and I get the unity greeter back.

Solution 2:

I didn't test it, but I suspect that @SampoSmolander might have the best approach.

Alternatively, I had success by removing the gtk greeter -- apparently this is what XFCE uses.

sudo apt-get purge lightdm-gtk-greeter

There still remains the tricky issue of getting rid of XFCE's mouse-themed greeter wallpaper:

• How do I change the wallpaper of the login screen?
• How do I set the LightDM wallpaper in Ubuntu 14.04?

Note: It looks like multiple desktop environments install the lightdm-gtk-greeter package (including XFCE and MATE). Interestingly, once you remove that package, the configuration files that @SampoSmolander discusses are no longer present.

Solution 3:

I had a similar problem. @SampoSmolander's answer might be the right way.

When using Ubuntu 14.04 you'll have to add the line

[SeatDefaults]
greeter-session=unity-greeter

into /etc/lightdm/lightdm.conf.d/50-myconfig.conf

I wrote a detailed how-to, but I don't know if it works, because LightDM reconfiguration seems to have solved the problem for me.

Solution 4:

cd /usr/share/lightdm/lightdm.conf.d && sudo ln -s 50-unity-greeter.conf 99-unity-greeter.conf and reboot the system.

The problem is caused by lightdm-gtk-greeter installing file called 60-lightdm-gtk-greeter.conf which overrides the unity greeter. I guess we should be able to just do sudo update-alternatives --config lightdm-greeter and select unity-greeter but unity-greeter package is incorrectly built and it does not support update-alternatives.

The above command workarounds the problem by creating a symbolic link with higher number so it can override the incorrect greeter selection. I'm using symbolic link to be better prepared for the future in case the file 50-unity-greeter.conf is ever upgraded by system package.