Installing via Steam. I set up an SSD for Steam and installed the initial DL to the appropriate folder, but then the main DL was pointed at the appdata folder on C:, I was unsure if this was a necessary requirement for the proper functioning of the sim and figured the way FSX scattered files all over the place I had better leave the install path as default, but my C drive is a HDD and I totally did not want most of the sim running from there, but when I tried to stop, uninstall and restart it would not let me change the path, even though the browse option opened up explorer, no folder could be selected. I had a look in the registry but it is not as yet referenced, so I am wondering if it will be possible to modify the path after install and move the files to the SSD.

This might do the trick.

Go to settings , Apps, Microsoft Flight Simulator App. There should be a "move' button, which lets you move the app.

Ill give that a try once it finishes, thanks fleng200 for taking the time to reply, appreciated.

Alas that was unsuccessful, it only moved a 900mb folder which then caused the sim to think it needed to download stuff again, so it obviously was unaware of the move, moved it back and all was OK again.