Instead of 188.8.131.52 you could use your ISP's DNS servers
echo nameserver 184.108.40.206 > /etc/resolv.conf
Suggestion - google dns configuration ubuntu & get rid of the big font (it's making me feel small )
I don't reply to PM's regarding BT and it's tools. Everything can be discussed on the forum so the community can benefit from it (if they bother to search).
Now to the subject - your computer doesn't know the names of the sites you'd like to visit (e.g. Google). So it uses DNS servers to resolve names into IP addresses (Google = 220.127.116.11). Now your computer tries to find a DNS server and doesn't know of any. So you let it know with the command above. 18.104.22.168 is a public free dns server. Your ISP has dns servers which are probably configured in your router. So you could also enter your routers IP for the nameserver (192.168.1.1)