One example of Microsoft holding back support is the xHCI USB controller in sixth-generation Skylake and seventh-generation Kaby Lake: Windows 7 doesn't support that USB hardware, so installing the operating system from a USB stick using those chips is tricky. Intel provides xHCI drivers for Windows 7 once it's up and running.
As far as I know, the xHCI spec is freely available, and so are the DDKs that let you write your own drivers (or perhaps port them from Linux), so I don't see anything stopping the enthusiast community from doing that, besides maybe (currently trivially circumventable, but who knows...) driver signing, and if my past predictions are any indication, that will likely happen.
As far as I know, the xHCI spec is freely available, and so are the DDKs that let you write your own drivers (or perhaps port them from Linux), so I don't see anything stopping the enthusiast community from doing that, besides maybe (currently trivially circumventable, but who knows...) driver signing, and if my past predictions are any indication, that will likely happen.
Ironically, there are already xHCI drivers for DOS: http://www.georgpotthast.de/usb/