Brand new 8700K and Asus prime Z370-A motherboard Already had a windows 7 image with the Z270-P EZ Tool applied, worked like a charm
Do your Intel USB 3.0/3.1 ports work? Have you got the drivers for Windows 7? I couldn't find any USB 3.0/3.1 drivers on Intel website. They do not support drivers for W7? Only Windows 10!?
Use ASMedia driver, as above this link he posted.. I had same factor problems, now it works fine in Win7 Pro.