Remove VirtualBox from Ubuntu
If you need to completely remove VirtualBox, e.g. because a new version install fails preventing future installations then from the Console run commands below:
List VirtualBox installations
sudo dpkg -l | grep virtualbox
Example below
sudo dpkg -l | grep virtualbox rc virtualbox-4.3 4.3.30-101610~Ubuntu~raring amd64 Oracle VM VirtualBox iW virtualbox-5.0 5.0.28-111378~Ubuntu~trusty amd64 Oracle VM VirtualBox
Purge these installations in sequence replacing 4.3 and 5.0 with your versions and answering ‘Y” to questions
sudo apt-get purge virtualbox-4.3 virtualbox-qt
sudo apt-get purge virtualbox-5.0 virtualbox-qt
After reboot you should be able to reinstall VirtualBox without errors