"The last time I used it was in 2007 (I think) and I'm reasonably certain I had it running under Windows 10 at that time."
- Typo ? Win10 was released in 2015.
However, there have been many changes to Win10 since the initial release, and some programs that may have been
compatible with earlier version\feature updates may no longer be compatible with the last few Win10 versions.
Particularly if the program in question has any unplugged security holes, such as the now defunct Adobe Flash Player
(Win10 is somewhat over the top on security).
"but if memory serves me it wasn't compatible with the older files which is why I still need the older one to install and run."
- I would be inclined to install the current version to refresh my memory. You may also want to try contacting the developers
of the program to see if you can change anything on the older files to allow them to be read by the new version.
- Window Compatibility Troubleshooter has never been much good, and if it's come back with a suggestion to use Compatibility with Win8,
that's proof positive how useless it is. If any Compatibility option were going to work with software of this vintage it would be
XP sp2 or Vista.
I assume you are trying to use Compatibility with the installer (Setup.exe or other file name used for the installer) on the programs disc.
If this does not work it is possible the installer is 16bit, which is not compatible with any 64bit Windows, but if the program is
recent enough to be compatible with Vista this is unlikely.
If the program uses a copy protection system (SecuROM, SafeDisk, etc ), other than a simple disc chec, the DRM may not be compatible
with 64bit Windows. I don't know if the same applies to productivity software, but a number of games released in the mid-2000's
have this problem with DRM.
However, with this issue the game will install, but not launch.
- Last trick... If you have access to another machine with Win7 try installing the program on that machine. Then copy all of the files
to a USB stick and on to your Win10 machine, and you may find the program will run.
.