I just installed Win 8.1 on my5k iMac internal SSD via Bootcamp. Everything went fine and it showed up in the Startup Disk preference, and at boot holding down the option key, as it should. Then, using Winclone, I backed it up to an external drive and got the successful message when it was done, which should make it bootable and available in the Startup Disk prefs, but instead neither one shows up, either in the Startup Disk pref or at boot holding down the option key. If I disconnect the external, the internal Bootcamp still doesnt show up in prefs or startup, even after a reboot, although it's visible on the desktop.. The only way to get it to show up as a startup disk again is by disconnecting the external and using a free utility called BootChamp. With that I can boot into Windows from the internal, and then, when I restart back into OS X the Bootcamp partition shows up in system prefs again. Without using BootChamp the only startup option I have is the OSX volume. As per the Winclone instructions I right-clicked on the external and chose Make EFI Bootable, and it does, but the disk still wont show up in any boot menu. Could it be that Im using a a FW > Thunderbolt adapter to connect a Firewire 800 external? Does it have to be a native Thunderbolt or USB3 drive? Or does anyone have any other ideas?