So at all the solution is change OS? I think it is better to find the failure and not change OS
I use Win10 (I use Linux also) for over 3 years on 30 rigs and i have found solutions for all issues but at the end i didn´t have much issues.
For me the better Mining Platform is Windows10, more flexible, more user friendly and so on.
But i think, to learn and understand mining is the best solution, if you understand it, than it is no problem to find the failure.
And by the way, this is not a OS problem i think. Have you tested every single GPU alone? Did you change the riser?
he only need to unplug his windows hard drive and have a usb stick loaded with smos plugged in.
The reason we ask for him to change the os to linux is more than what you think.
If he changes the os and it does not work.
It is 100% certain there is a physical defect.
Since he tested every riser 1 at a time
Since he tested every gpu 1 at a time
Since it all used to work.
Switching to linux and getting same result means a broken part.
It eliminates a sheath win 10 update that screwed everything up.
The only other thing possible would be physical and not a software setting.
Now to test further for physical is possible.
1) mobo has aged can no longer handle the load
2) mobo slot went bad.
3) a riser usb cable is bad.
4) psu has aged and can not handle the cards load.
If linux works he is then certain the issue is windows 10 software.
Only thing to do is try linux so he can determine if it is os or hardware.
It is impossible (very hard ) to do so with out trying linux.