want to change to KDE desktop
 

Hello everyone,
How can I have/use KDE desktop?
At the moment I use Ubuntu with Gnome desktop, (I did not choose it, it was the desktop default after installation).
Thanks

Well, its quite easy. Open up Synaptic or your favourite package manager, and search for package kdebase. Mark it to install, and all the necessary packages will be marked as well because of dependecies. This will install kde on your machine. After this logout, and on the login screen search the session button (like on the picture here). Here you can change which destop to use. After you selected KDE, just type the username and password, and KDE will load. Thats all.

http://www.google.com/search?hl=en&q...=Google+Search

Specifically the first result seems of high quality:
http://www.psychocats.net/ubuntu/kde

Err, of course it did. In a bit of confusing terminology, Ubuntu is the Gnome version of Ubuntu, Kubuntu is the KDE version, Xubuntu is the Xfce version...

Given that there is an underlying OS, you can install/add as many GUIs as you like. Although what you call it by the time you've got several is something of an open question.