Hi Pete,
Thanks for this, but no matter what I tried FSUIPC could not find any of the simconnect.dll regardless of which installer I tried. Also, as you mentioned, I could not find the simconnect dll's within the WinSxs folder despite them appearing to be installed fine as they even appeared in the control panel installed programs.
I vaguely remembered the mention of scndsk or chkdsk in some other thread regarding a similar issue. I didn't try this directly but when I tried booting up an old WIN 7 OS I have kept on another drive for some reason the computer wanted to run checkdsk on my WIN10 drive saying it needed it. I let it do this and when I was in WIN 7 I could now find the dll's where they were supposed to be on the WIN 10 drive.
Booting WIN 10 up again I checked and the dll's were still there where they hadn't been before. FSUIPC4975a then installed with no further issues.
Maybe someone else knows what has happened here but I have no idea and cannot provide a step by step solution other than running scndsk or chkdsk on the windows drive might help. This really was a trial and error solution.
Thanks again
Phill