CS757 'Blue' Cockpit

I think removing all the files may have been a mistake BUT, it makes no sense when after installing FSX only, the program does not start?

Makes perfect sense if you haven't done a compete uninstall. Many files are leftover from the partial deinstallation so no way can you install over the top.

And yes, it was definitely an error to remove all the files...

Well hard lesson learned.

I would UNINSTALL, NOT delete folders for whatever is showing in your ADD/REMOVE for FSX.

Then to try and fix your windows registry which is most likely a problem, try this tool from Microsoft...

https://support.microsoft.com/en-hk/help/928080/error-1722-when-reinstalling-flight-simulator-x

Then try a new FSX install and contact Microsoft via phone on activation first for the main FSX. Once that's successfully activated, install the Acceleration and activate that.

I use to uninstall/reinstall all the time to fix problems. In your case you ONLY needed to fix one aircraft while your FSX was working fine. I last installed FSX about 5 years ago and only fix the issues at hand. Got sick and tired of all the time required to setup FSX, which is the most time demanding of ANY software I own.

Live by the old saying, "If it aint broke, don't fix it"

If you can't get your boxed FSX working, perhaps you should get Steam FSX. However you will run into new issues installing some boxed add-ons to the Steam version.

Problem solved...re installed everything again but this time I installed the Acceleration Pack without flying first

thanks to everyone that contributed to my dilemma...much appreciated.