Thank you Jorgen. Revised complete version below. Advise if any further clarifications or changes needed, When final anyone can use as guide to first (or re)install.
Could also then post final version as new post if easier for people like me to find and use? ie "How to install FSX Gold on Win 10". David
"'1. Use Windows File Explorer to scan your C drive for the string "FSX", there may be folders there left over. If FSX was installed on a different drive, scan that one also. Uninstall both FSX and Acceleration, through uninstall in Control Panel. Reboot. Check everything is gone. (N/A if new install.)
2. Install the DirectX Redistributables - a free download from Microsoft. Reboot.
“There are also some other essential libraries that you may be missing that have not been mentioned by others...
You can use Programs and Features to check if you have any of the following 'libraries' installed or, if you wish, simply download and install them - the installers will check for any previous install and will replace any missing/invalid/corrupt files or install the complete package as appropriate.
Visual C++ Runtime Redistributable packs - specifically version 2005 and 2008 but I also recommend installing 2010 as well. You can find download links for earlier version HERE
You will need to download the both the x86 and x64 versions. Click on the required link and a standard download option box will appear - DO NOT run the installer from this but select the Save As option and save the file to temp location. To install, right click on the file and select the Run as Administrator option. Install each package separately, starting with the oldest version, and reboot using the RESTART option between each install. The reboot is essential to allow the windows registry and important system files to be updated.
.NET Framework - specifically versions 3.5 and 4 - download from HERE - download and install using the same procedure for the C++ files.”
3. Run Windows Update, make sure the switch under "Advanced Options" called "Receive updates for other Microsoft products" is turned on. Run the update until there are no more updates to get.
4. Install FSX Deluxe (2 disks) remember to change the path it installs to. What you need to do is to install it OUTSIDE the reach of UAC, that means in C:\FSX or something like that, but absolutely not under C:\Program Files (x86) where it wants to install. Then you need to set it to run as Administrator. Turn UAC off also, if you are OK with that. At the end of the installation, fly around a minute or so in the ultralight, then end the flight. Now reboot.
After installing FSX DeLuxe (the 2 disks), flying around, shutting down and rebooting you need to activate FSX DeLuxe! Then reboot again.
5: After the last reboot in bullet point 4, install the third DVD from the FSX Gold set, the Acceleration DVD. Again, at the end of the installation of that, fly around a bit, shut FSX down, reboot, register/activate with the code from the Acceleration DVD and reboot again."''
