Apologies - I should have mentioned that I had checked all that
I have since had assistance from PC Soft
"This problem can be related to the MSVCR71.DLL which is missing on the host computer. You may copy this DLL from the WinDev /programs/ folder to the same folder as the WD120SAPA22.DLL."
This indeed fixed the problem for me - worth noting for anyone else who may encounter the same problem
Thankyou for your assistance Ken