True, that many FSXers do have problems getting their Sim to install/activate/launch/run properly in Win10, but at the same token, there are many who have had no such problems. That scenario itself tells me that FSX is not the problem, nor its continued
functioning in all the Windows versions from XP to 10. Users need to look elsewhere on their systems to find out what is causing their FSX problems. Of course, we don't know how well FSX (now an ancient piece of software), will function with any next generation
Operating Systems from MS.
Dovetail Games have indeed obtained a limited licence to make changes/improvements to the original FSX Deluxe Edition and they seem to have done a superb job, remaining within the limits of MS' requirements and agreements. As you know, after FSX, MS produced
MS Flight which was produced to presumably garner in a wider cross-section of the community. Having downloaded and used it for trial purposes, I found it too 'game-ish', offering nothing of worth to anyone wanting to engage in serious flying or develop their
real world flying skills (esp. in navigation). Yet some still use MS Flight and downloaded additions to it and enjoy it. However, MS have also ceased development with this 'game' and it has been sucked into the same 'black hole' as FSX.
So it was good that Dovetail Games had enough foresight to add FSX to their large offering of other Sims, as of course as you mentioned, Prepar3d, X-Plane, etc have also likewise done. And remember, these non-MS producers of Flt Sims are also continually
re-working their products which include making them functional with newer Operating Systems. MS for now, appear to have discarded any further development in Flt Sims and we are left with an old FSX that one day will be relegated to the trash heap. We just
have to move on to better offerings if we are to continue to enjoy our 'hobby'.
A brief write up on the MS-Dovetail deal:
http://www.dovetailgames.com/news/2014/jul/9/dovetail-games-licensing-deal-with-microsoft-takes-flight