How do I go back to KDE splash / login after installing XFCE?
Solution 1:
splash screen is configured by the alternatives system... you can get a list of available plymouth themes by doing: update-alternatives --list default.plymouth
You can then change the current plymouth theme by doing
sudo update-alternatives --set default.plymouth /lib/plymouth/themes/kubuntu-logo/kubuntu-logo.plymouth
The alternative way of getting Kubuntu splash it to remove package xubuntu-plymouth-theme.
To change the login screen you can either run sudo dpkg-reconfigure gdm
and choose kdm as mentioned in another comment or remove gdm which should set kdm as default display manager.
Solution 2:
You can just switch back the display manager to use kdm using
sudo dpkg-reconfigure gdm
and then selecting kdm.
Solution 3:
From a terminal:
sudo apt-get remove xfce4