So I followed this excellent guide to install Windows 8.1 to my external USB 3 drive. It works great and the SSD and USB 3 combo make it super fast and stable after installing the bootcamp drivers. Only issue, is cosmetic. When I option boot, I get two icons for the external drive, Windows and EFI Boot. The Windows partition boots as expected, but the EFI Boot does nothing. I just want to hide it. I tried deleting it, and the Windows partition then stopped working, so I know its needed. Can I hide the EFI Boot partition from the option Statup Manager?