I turned on Rapid Storage in the BIOS however when booting in to Windows 10 it reported missing boot partition or some such (during loading)
Ah, thought that maybe so. What is odd is that when Intel Rapid Storage is tuned off in BIOS it boots on a single drive perfectly well. When booting the same single drive with Storage turned on it starts the Windows 10 boot process then promptly stops.
I would expect this to be the case; a single drive *should* work (sadly, life doesn't always meet my expectations <g>)