The strangest thing has just happened. I was going to follow your instructions, but my computer room has been a mess for a while. So I decided to clean the room properly and then sit down with a clear head and work on your instructions.
I took everything to bits, cleared the room up, hoovered and then put everything back together.
Switched the desktop back on and hey presto, I'm back on the internet without installing the driver.
I've no way of explaining why, maybe it was just a bad hardware connection somewhere.
I'm sorry if I've wasted your time, but if it's any consolation, I've learnt from our exchanges and the room looks great now!
Thanks for your support.