Booting from Windows 8 To Go drive on a 27" Mid-2011 iMac

[VioletProcyon]

Hey there, I have successfully installed a Bootcamp copy of Windows 8 Enterprise (to go) on my USB External HD and it boots onto nearly every computer I've tried it on, I only have one issue though and that is getting it to boot on an iMac.

One thing that confuses me is the fact it boots up perfectly fine if I use a MacBook Pro (2012), appearing in the alt-boot menu on startup as an orange Windows hard drive. If I do the same on the iMacs, the USB drive doesn't appear at all in the boot options. However, if I boot to the desktop and go to the startup disk selection, the external Bootcamp drive appears in there, I can select it, although if I boot onto it I just get the error "No Bootable Device Found". The same error occurs when I boot via rEFIt.

Any suggestions on how I could get the imacs to boot onto the drive? or am I just out of luck. I'd find this useful because my college works primarily with iMacs and I need them to use windows specific software since I don't have access to any windows machines.

[djjkxbox360]

Does the iMac have the latest Software updates/OS? I'm not really sure if it's possible, if it works on the MacBook Pro, then the bootcamp drive definitely works, so I don't think think there's anything more you can do

[.Lain]

IIRC any iMac with an optical drive* won't boot from USB.

[editline]29th March 2014[/editline]

*don't quote me on that, but i definitely haven't had any luck getting most iMac's EFI to co-operate with a USB boot
and now that i read it, specifically the model you're having trouble with. i couldn't find any work-around for it. make sure the OS is fully updated, and try again

[VioletProcyon]

[QUOTE=.Lain;44390745]make sure the OS is fully updated, and try again[/QUOTE]

One of the machines in the suite has Mavericks installed, the bootcamp drive appears in the startup options but not the alt boot menu. The last thing I'm going to try is burning a bootloader called PLOP to disc and seeing if I can route it to boot via that (probably won't work though). The imac just seems to completely ignore USB devices during EFI boot.