I have a just built ASUS P9X79 Deluxe MoBo w/ 256Gb SSD, 128GB SSD scratch drive, 500GB and 2TB HDD. It will not boot. Have to go to BIOS (F8) then look around, exit and sometimes the 256 is recognized and it will start. What did I do wrong? This happens every time. I get Windows Boot manager w/device is not accessible message. How can this be corrected?