Unable to connect to authorisation server

Like an awful lot of other people here, I'm unable to authorise my laptop.  All I get is an error saying I can't connect to the server and to check my internet connection.  Tried the chat line, who were completely clueless and sent me here.  All I can see is a whole bunch of people with the same issue and no replies.  I'm using version 4.5 on a Windows 7 machine.

At least I only spent a few hotel loyalty points on a book, but I would actually like to read it.  I'm really not getting good vibes and will most likely never use this software again.