I exited that scam website without paying the $30, and then checked the connection, finding the suspect cable. Then I searched in the old AFPDL box and found a spare connector cable, included free of charge by Sussex Model Centre but surplus to my requirement at that time and long since forgotten. With this, Bingo - everything worked fine!
Then, this morning I decided to check the graphics driver anyway, and found the genuine Nvidia website, downloaded the latest driver and selected the quick installation (recommended). The routine extracted the existing driver but the installation of the new one failed, so I tried again, this time selecting manual installation but it still failed. Giving up on this, I checked to see if Aerofly could still be opened, and it couldn't , so this afternoon I took the PC to the dealer, who sorted it out and advised that where drivers are concerned "if it ain't broke don't fix it"!
Many thanks for all the help and advice. I must say it has been worth the effort. I am not an expert model flyer and haven't tried all the features of AFRC7, but many are immediately apparent, such as the ease of setting wind direction and being able to view all of the flying field, move the model's position on the ground etc.