The Ubuntu default desktop uses the Gnome window manager, which can be a difficult transition for Windows users.
Hit the Y key to proceed, and let the install begin.
I decided to leave the default gdm.
Here we will click KDE to continue.
Login, and you should now see the KDE desktop!
When I experienced this problem, I was also unable to use the mouse.
You will probably see that your xorg.conf file was backed up to xorg.conf.1 during the KDE / Kubuntu installation.
Just copy the xorg.conf.1 back to xorg.conf, reboot, and everything should be fine.
Again, don’t mess with the xorg.conf file unless you are actually experiencing this problem.
