There are two (at least) issues here. One is the business about Microsoft and inability to make version 1 of anything work properly (although some Windows releases have been worse than others). The other, maybe more relevant to this forum, is whether Windows is an appropriate platform for CNC machine control anyway. I think the honest answer to that is, and always has been, no. We have been misled by Mach3 and the black magic performed by its creator to believe that Windows is OK. Never has been more than "good enough" in some situations, which is why there have been so many external motion control solutions developed (was SmoothStepper the first? Not sure - wasn't active in this area at the time). Linux isn't actually more than "good enough" either - performance with LCNC still has hardware dependence that is unpredictable without testing specific boards and hardware configurations. That's because some of the issues come from the underlying hardware anyway, as well as OSs that were never written with real-time control as a goal. They can work fine, but it's unreasonable to expect Microsoft to do anything to support what was in reality no more than a backdoor bodge. I'm not knocking Mach3 - that it worked at all, and well enough for many home and hobby users, was a brilliant achievement, and I use it myself (although with an external motion controller).

Will the future be open-source via Linux, maybe with the aid of motion controllers like the Mesa cards, or will it be something like a descendant of grbl, running on bigger, faster hardware than it does today? Or Boyan's favourite Chinese box with proprietary software?

I was happy with Win7 but have updated all my machines to Win10. I have six Intel PCs which are running fine. I have one AMD machine with a year-old motherboard which runs like a dog. I ended up using my laptop to finish a job on the router earlier today because the AMD PC couldn't even manage to keep the network connection open to the CSMIO. No idea if that is AMD or Microsoft's fault. It's not just Microsoft, though - I can't run the latest version of Mach3 because it does not work properly with the CSMIO (although there's a lot of finger-pointing about that problem). I'm expecting to go open-source, probably Linux, one day but at the moment I'm taking the pragmatic Win/Mach3 approach because my CSMIO won't work with anything else. Might end up "upgrading" the garage PC to Win7, though, if my key still works...