Thanks for the prompt reply pete,
You were right about the gf drivers and the missing file, although the gf-45 modules worked fine (just not with 737 ng PMDG) it seems as you correctly sugessted they were working with the old go flight drivers!
I also noticed that go-flight have made available a new gf-keys software to enable simple and more effective key mapping for most of the gf products, which works very well, as I am now able to control all auto pilot functions of the pmdg 737 ( the only drawback is the actual display on the GF-45's not being in synch with the aircraft, but its a small price to pay!)
It may be worth noting that each rotary control of each gf-45 unit can be assigned any two key functions using the new GF-keys drivers, thus allowing even more functions to be utilised.
again many thanks for your prompt help,
regards, Mark D. :lol: