I've been searching around for this for a while, but I haven't found anyone else with the same problem. Guess no one made the same stupid mistake.
I have a Windows 7/Ubuntu computer that is suffering from Windows 8 Fast Boot. I can see how this might be an uncommon problem to have, so I've written out how I managed to get myself into this predicament below.
I'm on an Alienware 14 that originally had Windows 7. I installed a second hard drive and got Ubuntu working on it no problem. I didn't think I touched the original hard drive at all, but when I was done, Windows was refusing to boot. I tried to fix it and eventually gave up. It wasn't a big deal. All my stuff was backed up for that reason anyway. So then, I tried to reinstall Windows from a recovery USB key I have by going through the BIOS boot menu, but the computer wouldn't boot from the recovery flash drive unless I picked the UEFI option. I went ahead and reinstalled using the UEFI option and Windows was working fine again, so I thought "this is great!" I then went back into BIOS and disabled the Legacy ROM thing. An option for Windows 8 Fast Boot was now available and enabled by default. I turned it off because I didn't want it, but then turned it on again later, not realizing it would cause great harm.
Now, through a great series of steps, I have Ubuntu installed on the first hard drive rather than the second (which is not a problem) and a Windows 7 installation that can't boot or repair or do anything on the second. I want to reinstall this Windows 7, but I have no way to access BIOS or EFI or whatever the correct term is. Because of the enabled Windows 8 Fast Boot, there is no option to enter BIOS on startup, and I don't have Windows 8 to turn off the setting. I've tried pulling my laptop completely apart to unplug the CMOS battery. That didn't work. It still doesn't let me get to my BIOS on startup.