This error indicates that the Windows 7 disc is not able to get disk and partition information from the BIOS\motherboard. This could be due to some sort of problem with one of the hard drives. Try unplugging one of the hard drives, and see if the disc will boot properly. Try this with each of your three drives. And verify that NO removable media (external drives, SD cards, etc) are plugged in to the computer while you do so.