Missing internet and desktop icons after repaired upgrade to 14.04

I see some similar but not identical questions so I prefer to ask here:

I tried to upgrade from 12.04 to 14.04 but the upgrade blocked (no error message) after running for perhaps about an hour (at a line containing “trusty/main textlive-latex-extra-doc”).

I used the rescue method and after installing the “held-back” packages the system booted and worked (execpt that the log-in page still said 12.04). Then I did the last step in the method and ran “apt-get autoremove” and rebooted.

Now I have no internet (neither fixed nor wireless) and no desktop icons (although the menus and user task bar icons are there and work). What to do – I think that the first thing should be to get the internet back?

Waiting eagerly/urgently for your help, best wishes, John