Thanks bobkn. I saw that on the Asus site and I guess the other drivers are the unknown.
I have many Windows 7 system images but wouldn't want to buy an OEM non SLP license just to try it out - but...

I've been running Windows 7 on a P8Z68 Deluxe with an i7 2600k cpu for some years. Getting old but it performs well.
It looks like this combo may not be compatible with Windows 10. I'd appreciate...

Windows 7 because it's the most capable OS I know a little about. I'm keen to see what Windows 9 has to offer.