Hi,
I'm dubious that its anything to do with the OS. Clearly in order to use Win10 you have to be using an external motion controller. The PC
provides PVT (position velocity over time) data to the controller and the controller handles it from there.
To my knowledge Mach runs on Win7 or Win10 without problems. User Account Control as applied in Win7 requires that Mach be run as Administrator
it doesn't change how it runs or the PVT data it produces.
I have two licenced copies of Mach4, one on my machine PC, a dual core Atom with onchip graphics, a real gutless wonder, and my i7 16Gig laptop.
The Atom runs 32 bit Win7 and the laptop 64 bit Win8. Aside from the Win8 machine loading big files faster and regenerating graphics way faster
both run my machine just fine. No difference in speed, accuracy or anything else. I suspect if I monitored the PVT buffer I might see the laptop being
able to keep it full but having said that the little Atom doesn't run out of data anyway.
Once you get away from the parallel port and the restrictions/requirements that it brings then Mach3 or Mach4 will run fine on just about any PC from
about Win2000 onwards. Just pick an OS that you like, work out the details necessary to get that OS to run Mach and cut chips!
Craig