Lubuntu-Desktop not working on Ubuntu 14.04

Question

I recently decided to install LXDE on my Ubuntu 14.04 (it's not a fresh installation, however it's quite recent). I wanted to use mainly Unity and use LXDE sometimes when I needed higher performance. Following a guide to do this, I used:

sudo apt-get lubuntu-desktop

for getting the Lubuntu flavor. After everything finished I shutdown the computer, for some reason. To my surprise, the shutdown screen as well as the boot one has the Lubuntu logo instead of the Ubuntu one. A minor annoyance as it was nowhere written this would be one of the effects. Then, contrary to what I was made to believe, the login screen is the Lubuntu one. I couldn't find any way to choose the desktop environment from there so I just log in. After I login I see that the desktop is still Unity. To sum up: my LXDE installation made my Ubuntu believe it was Lubuntu, but left the only aspect I installed it for unsolved. After this experience, I decided to uninstall it using these commands:

sudo apt-get autoremove lxde
sudo apt-get autoremove lubuntu-desktop
sudo apt-get --purge remove lxde
sudo apt-get --purge remove lubuntu-desktop

The last two were not necessary, apparently. These operations left the situation unchanged. It also appears that the Lubuntu login screen just covers up the Ubuntu one as for a brief second it appeared after logging in. So my questions are:

1. if and how can I reset my system to its former state, and
2. can I then install LXDE with the ability to choose between the DEs and hopefully be able to use the programs from Unity on LXDE (ideally without installing its own software again)?

Thanks in advance

Answer 1

Go to Synaptic and search 'Lubuntu' and mark for complete removal.

In Synaptic remove lxdm (login manager for lxde) and also check if following packages are installed : unity-greeter and lightdm. Install them if they are not. if you prefer terminal-

sudo apt-get remove lxdm
sudo apt-get install unity-greeter
sudo apt-get install lightdm

also:

sudo -H gedit /etc/lightdm/lightdm.conf 

You'll enter a greeter configuration file. There find the line

greeter-session=unity-greeter

if the line does not exist, add it.

Just install 'LXDE' instead of lubuntu-desktop. It works the same, but won't show on startup.

sudo apt-get install lxde