Now I have a big problem. I got the window 7 disc to load and attempted to install it (the computer would not boot from USB, it says that there is no USB boot option). Windows 7 was unable to create a new system partition so I tried deleting all partitions on the drive (a second blank hard drive). Now the computer won't boot at all even with this hard drive removed, it tries to boot from the ethernet port without a disc, using the install disc I can see that the original partitions are still intact. Beforehand I changed the boot mode to CSM as instructed in one of those tutorials. What happened? This new EFI system is giving me lots of problems.