Dear friend I narrowed it down to the WD Green 2TB HD. Its not compatible with the no DVD Bios. Both Xboxs that I tried the M8 NODVD bios had the Green 2TB with SATA Adaptors made by kingwin. Its not the BIOS its the WD Green Crap. I tried an IDE WD 500GB Blue and a stock Xbox drive and both xbox boot fine with the NODVD M8 Bios. But weird thing is M8 with DVD Support, IND and Executer have no problems.