When I bought my current Dell Inspiron 3552 - http://www.dell.com/uk/p/inspiron-15-3552-laptop-ubuntu/pd - Ubuntu came preinstalled. I was new to Ubuntu and I did not feel ready to install an OS. I had so much else to learn. That was almost a year ago. Can I move from 14.04 to 16.04?
A previous answer on askubuntu said yes (Is it necessary to upgrade to 14.04 LTS or can I stand in 12.04 LTS forever with no problem?). Earlier versions of Ubuntu would cease to be supported so I did try to update. However the screen went blank. With some help from Dell I reinstalled 14.04 from a USB stick. I consulted Google and discovered that I was not the only one to encounter difficulties.
I'm currently only using this laptop to learn the command line and Python and general Ubuntu housekeeping but my ambitions will grow. I may need the greater protection that a newer OS might provide. Is it possible to migrate from 14.04 to 16.04