The problem has been solved by my son. It all happened over the telephone and I gathered that something was set to static instead of active. So I commented out some lines using gedit, saved and rebooted. Network Manager became active and the router is connected to the internet.
Thanks to all who tried to help. Norman -- [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk https://wiki.ubuntu.com/UKTeam/
