Microsoft stirred up a storm of complaints when it announced earlier this year that effective July 2017 it will no longer support Windows 7 or 8.1 on the newest Skylake Intel processors. Reasons for the decision ranged all over the place, but came down to this:
For Windows 7 to run on any modern silicon, device drivers and firmware need to emulate Windows 7’s expectations for interrupt processing, bus support, and power states — which is challenging for WiFi, graphics, security, and more.
A similar situation — but in reverse — is now playing out with older Intel processors and support for basic Windows 10 features.