When you install Kubuntu from inside Ubuntu KDE will automatically overwrite the default (Ubuntu) cursor theme. If you use GDM a lot you’ll probably want to revert back.
KDE and GDM cursors on Ubuntu
This will require you to restart GDM which will log you out so finish what you’re doing. Then fire up the terminal Applications > Accessories > Terminal and enter the following command:
sudo update-alternatives --config x-cursor-theme
The default Ubuntu cursor theme is
DMZ-White/cursor.theme (typically listed as
Enter the selection number to the left and hit Enter.
Now you’ll need to restart GDM for it to take effect. Via the terminal enter:
sudo /etc/init.d/gdm restart
You will be logged out and the once GDM starts again you should have the default cursor theme back.