Problem now sorted - the clue was in the DNS not resolving.
The installation instructions required the PC to be setup with a Static IP address and the router to be setup with a dynamic address. The problem was that setting a static IP address also resulted in a static DNS address of blanks.
So I ignored the instructions and setup both the Router and PC to allocate addresses dynamically and activated the DHCP feature and the job was done

Would just like to say a big thank you to the guys who jumped in to help - when it's all going belly-up and you can't get anything from the manufacturers it's good to know that there are people out there who are prepared, even eager!, to help out.
Cheers guys......