Ubuntu 16.04 will not load properly.

When I switch on my PC, containing Ubuntu 16.04 it goes through the process of loading BUT stops without displaying the operational icons and can not be used.
I tried to install, - after typing Control-Alt- F1 which did something like the Terminal - sudo apt-get install unity BUT nothing happened,. After that I tried: mv ~/.config ~/.config-backup and nothing happened.
So what should I do to restart my system? Your help would be most appreciated to <email address hidden> which I could read on my wife's laptop.
Many thanks in advance, Bela Yorke, UK, postcode 8/IG10 1QE