You can go into bios without a keyboard through windows. But when I have my USB plugged in there is no USB option in boot overide. I also tried it with an otg cable and same issue. Anyone having the same issue?
Was your Windows USB drive created by Rufus? I had issues with the USB created by the Media Creation Tool (i.e. not bootable) when I changed to Rufus, it worked.
I’ve just installed Windows 10 over Windows 8.1 on my x98 (originally HG6M). After three days of battling with it, eventually it worked this morning. I couldn’t get it to see a USB key and updating via Windows update failed, so I managed to get it to work from a copy of the installation media on an SD card. Of course it needs to be started from within the existing copy of Windows.