sudo software-properties-gtk
1. go to the main tab and remove all selection and select close. ( Let the list update)
2. run the same command, select all options and apply close letting the list update.
3. now you can run the same command go to Additional Driver and install the Nvidia driver.
Problem: ( Ubuintu-16.04, issue with software properties not saved properly)
The following packages have unmet dependencies:
nvidia-460 : Depends: lib32gcc1 but it is not going to be installed
Depends: libc6-i386 but it is not going to be installed
