I have a laptop that currently runs Windows 8 and Ubuntu 16.04 in dual boot mode. Both OS are installed on the same HDD but on separate partitions. I would like to upgrade from Ubuntu 16.04 to Ubuntu 18.04 but keeping Windows 8. Is it possible to upgrade ubuntu without affecting the windows partition? If so, which is the safest way to do it?
Should I use a live USB/DVD? Should I use the terminal? or the upgrade program that alerts me of the new release and offers an upgrade?
My goal is to upgrade from 16.04 to 18.04 without affecting windows and without losing data (I have a backup of my files anyway).