Even if Windows sticks with 1 operating system, which I find unlikely, they will still have updates to it. All I can do is estimate what will happen, so anything is possible, but what I find probable is that Windows will stop charging for the latest operating system, although it will keep evolving. Windows 10 should be able to run your programs at any point, unless they change the architecture of windows, which is likely with the growth of artificial intelligence and virtual reality. However, future proofing hardware would be less likely, with the addition of updates and new features into Windows 10 the OS will need more ram and a better CPU all the time. Windows 10 may even do the opposite of future proofing hardware, unless you don't get any updates to Windows 10, in which case nothing is different from Windows 98 in that aspect, I still use a Windows 98 almost daily at my work and it runs just like it used to when I first used it. It has not been connected to the Internet in 10 years or more, which is the only reason why. So basically what I am saying is future proofing software is likely, but it will likely require better hardware faster than ever before.