It seems to be related to IDE/AHCI/RAID drivers.
If you always used the old board on AHCI or RAID, your installed Windows won't boot because the new board requires new drivers.
However, you already used IDE mode, your Windows will have IDE drivers also, and so it will boot with the new board if you configure the SATA interface to IDE in BIOS.
You may try first with the old rig, put it on IDE mode and see if it boots.
Good answer thank you. I will test this & report back.
Perfect advice, thank you.