Delete the displays and their driver (and the hidden ones) from device manager.
Thank you for your prompt reply, however I have tried to do that before I got to the forums.
I uninstalled the AMD drivers, deleted the folder on C: all folders under ..c:/amd. Simply reinstalled. The 2nd monitor has never been visible in the device manager, only one, even with the drivers uninstalled.
Possible solution. Do you have a registry key cleaner tool? or point me in the direction of the hkey to amend.
Naturally I know about the registry and accept liability of corruption, if I break it.