Will I get Kubuntu CD with Ubuntu CD?
Basically their only difference is in the desktop environment used: Kubuntu uses KDE, while Ubuntu uses Gnome. Under the hood they are pretty much the same. You can install the KDE desktop environment alongside with the default Gnome desktop environment. Just go to the Synaptic package manager, seerch for “kde”, select and install. After that, you can change your desktop environment by logging out (choose “Log out” instead of “Shut down”) and change the desktop environment in the GDM screen (where you type in your username and password when you power up your computer). If I remember correctly, you can choose a different desktop environment in the GDM screen under the “Options…” menu. This applies to any alternate desktop environment or window manager you choose to install. You can always change back to your original Gnome in the GDM screen.