Sorry, I thought I had given sufficient detail for the problem I was asking about.
The problem - my DCS install is under Steam - shows in the Steam library and runs only from the Steam folder in my start menu.
I d/l the install files from the DCS site NOT Steam (7 files took over 8 hrs to d/l).
So the question is how is it that it is appearing under Steam?
The subsequent problem is that, as Support tell me, I cannot install modules d/l from DCS into the 'Steam version'. But as I say above I never d/l or intentionally installed the 'Steam version'!
I am loathed to spend another 8 hrs d/l again if I am going to find again that it has installed under Steam and I can't install the modules I have bought.
Hopefully that explains better?
Thanks
Nigel