weird, have you tried with just the os drive plugged in?
I've got this vague recollection of there being issues with some setups when the drive is using mbr rather than gpt and you need to change a setting to allow compatibility etc.. My drives were all fresh so no idea on that one though.
ftpm might be another issue - personally I have this turned off (windows 10 anyway) because it was causing some micro stutters, even with the latest bios.
Don't forget your pbo and curve optimiser etc too
Just a side note - your bios will probably reset when you do a bios update (mine did) so make sure you take note of all your settings.
Think I've just about got her working! For now at least!
Played about with some BIOS settings but I think the one that did it was in Settings/Advanced/Windows OS Configuration then swapping the BIOS mode from UEFI to CSM which seemed to allow the boot!
One thing at a time! Haha
A VERY good idea! Taking a picture of every setting I change JUST INCASE!