Many thanks to you both for your help. Pasting the panel.cfg for the default GPS has worked. Its a case of knowing what to look for and without you I hadn't a clue.
I have downloaded two payware WWII aircraft recently but neither comes with GPS. I have tried, unsuccessfully, to install EZ-GPS in them but it is just not recognised. Has anyone come across this problem and do they have a solution? I know that GPS is only a recent innovation in the real world but it is difficult to fly classic aircraft without it.