Sometimes we want to have 2 or more desktops ,sometimes we want to remove 1 or more desktops,right?I have just removed kde4 from Ubuntu.By the way,I summarized some tips for installing/removing desktops in Ubuntu as follow:~

NOTE: I don't guarantee below tips will work in every Ubuntu versions,but they should work in >7.04 versions.

1.Install/remove  KDE :

Install

sudo apt-get install kde

or

sudo apt-get install kubuntu-desktop

for installing KDE4:

sudo apt-get install kde4-core

Remove :

sudo apt-get remove kdelibs4c2a libarts1c2a

or

sudo apt-get remove kubuntu-desktop

for removing KDE4 :

sudo aptitude purge kde4 kde4-core

2.Install/remove Gnome:

Install:

sudo apt-get install gnome

or

sudo apt-get install gnome-desktop

Remove :

sudo apt-get –purge remove liborbit2

or

sudo apt-get remove gnome-desktop

3. Install/remove Xfce

install:

sudo apt-get install xubuntu-desktop

Remove:

sudo apt-get autoremove xubuntu-desktop xfce

--End--