Many thanks for the input Glenn and all the trouble you went to, I do appreciate it.
I uninstalled TMG again, removed all the TMG folders in the windows paths; I re-read all your advice; checked all the settings, redid the data-paths.txt file and the instructions for it in the TMG help file before starting the new install of TMG.
It now is working as hoped for (apart from resetting the exhibits which comes later).
Many thanks again.