not sure what the lowest spec machine is for win 7, but if win 10 has to fully support this then nothing is going to improve/advance along with features
10 will still work on the older hardware, but after so long newer features will not be available or possibly not upgradable
pure speculation anyway at this point, so a while before we know what will happen
Personally I got a new PC just so I could use Win10 properly.. my previous PC couldn't run Win8 due to chip set issues.
If you are going to hold onto a computer past ten years then you should expect to start having problems with an OS. Apple did it with one of their upgrades to OS X several years ago. This upset quite a few users, albeit Apple stuck to their guns, and did not change the OS for the older systems. Sometimes you just have to bite the bullet and upgrade or just live with what you have. . .
Hmm, Interesting that I still have an old windows 98se system that still works without issue and uses clamwin (Old version) as a virus protection. My point is there nothing wrong with my windows 98se operating system. I am not talking about parts, just the operating system. I do need a few parts, network card do to a electrical surge, CD/DVD being warn out it still works some. I could use a hard drive because it also warn out but it still keeps on running.
As long as it's physically sound it will run anything from that era but don't expect anything new to run on it. I have repaired and maintain an 386 Sx 16 for a friend, and it's still used as controls for industrial band saw. It has windows 3.11 on it but nobody's expecting it to run 64 bit programs or to go to internet. It would be just too unrealistic to expect W 10 to work on it. A computer is not only HW but OS and SW, any of those missing and it's a door stop.
For OS to go a generation of HW back, OK but anything older than that would just drag down newer stuff. Why should I be expected to pay for somebody else to be able to run some museum belonging computer with newest OS.