I was using our travel laptop to swap some files around and try and get some order into our HDDs but for some reason it wouldn't connect with the wi-fi.
I had a similar problem a few months back and ended up delving into IP and DNS settings via lots of research on the web but having solved the issue (eventually) of course I didn't save the relevant pages and tutorials.
I feared the worse and once more spent time and effort trying to resolve the problem with no joy when the same thing happened to our main computer which is linked to the internet via LAN cable.
I then did what I should have done from the beginning and simply rebooted the router which did the trick after a few nerve wracking minutes. Phew- all now seems well again.