I am new to KDE. I installed KDE 4.4, and setted up LightDM as default DM. After that, I added kubuntu-ppas/beta PPA and upgraded to 4.9 from it. After upgrade, KDM set up as default without prompt dialog. I tried to change that in /etc/X11/default-display-manager, but LightDM is already in it. Are there any chance to remove KDM and set up LightDM as default?

INFO:
System - Ubuntu 12.04.1
In /etc/X11/default-display-manager:

Code: Select all

/usr/sbin/lightdm

There is Unity, Unity 2D, KDE 4.9 and Chromium OS (Aura) session.

UPDATE:
I also tried with this, but problem is same.
When try any solution and reboot here is nothing.

Have you tried setting the display manager by running the following?

Code: Select all

sudo dpkg-reconfigure lightdm

According to the Kubuntu developers this is the most official way to set login manager.

I tried that.

I solved problem with

Code: Select all

sudo dpkg-reconfigure kdm

Also, please note that the Beta PPA contains KDE 4.10 RC3 at this time - and not KDE 4.10.

I am using kde-plasma-desktop (4.9) from that .

Now new problem. When I rebooted there is again KDM! First time then rebooted all works. 2nd time KDM went back. I tried

Code: Select all

sudo dpkg-reconfigure lightdm

and

Code: Select all

sudo dpkg-reconfigure kdm

but nothing, I select every time lightdm as default but same problem.

Have you tried selecting KDM as your preferred option, rebooting and then reselecting LightDM?

My problem is lightdm-kde-greeter. I changed greeter and now all looks OK. Sorry for my error.