Folk that have tried yanking out Win 8 & 8.1 and trying to install Win 7 are apparently having many problems with driver incompatibilities. So even trying to get a later OS than XP on to new machines with Win 8 flavours seems doomed.
Vista was an almighty disaster for Microsoft but fortunately, Win 7 came to the rescue, Win 8 is turning out to be an even bigger nightmare than Vista, and if Windows 9 does not pull Microsoft out of the mire this time, I think that it would be a pretty safe bet on seeing Microsoft declining rapidly in the marketplase of OS's. Let's face it, there is a limit as to how long you remain clever and good at what you can produce to please the masses. I do accept that Apple do a pretty good job at staying ahead of their game, but then again, their technology is not down at the same level as Win 8, is it.