I would actually love to see a full, from-scratch rewrite of Windows. I'm not sure if it's ever been done before, but it definitely feels like it hasn't.
It was even on the verge of being a microkernel and it could run a super light weight virtualization (for the lack of a better word) system: OS personas.
It would be interesting to get Windows NT NextGen, true.
Currently, they're at around ~WinXP level support
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