Combining PCIE SSD and Raid SATA SSD

[pawinda8]

I have a new ASUS Z170 Pro Gaming motherboard. I have a Samsung 950 Pro PCIe NVMe SSD mounted on the M.2 port. I have two (2) SSD's, 1 on SATA-2 and 1 on SATA-3. Windows 10 is loaded on the M.2 SSD. I'm trying to setup my two SATA drives as RAID 0, but each time I set SATA config from ACHI to RAID, I lose my M.2 drive and system won't boot. Does anyone know of a way to keep Windows on the M.2 drive and configure SATA ports 2-6 as RAID?