My thanks to Denis who finally got me on the right track. It would appear to be the address in the UCAC4.tdf file that was incorrect. I had c:\ucac4.txt
whereas Denis advised that it should be ucac4.txt and that works!!!
I used the guide.dat and ucac4.tdf files that Denis sent me on my desktop PC but just changed the above line on my laptop and all was revealed.
Regards