I have Ubuntu 12.04 installed on a External drive. It boots up on my laptop without problems but when I try to boot it on my desktop, it gets stuck on a black screen with a blinking underscore. (I boot it through bios and selecting USB. Grub does not show up)
I've checked around and it seems that this could be a problem from different boot modes between UEFI/EFI and legacy. I found out that Windows should be on legacy mode (I found online to 'use bcdedit /enum' in cmd and since my Windows Boot Loader path ends in .exe, it should be legacy).
Ubuntu 12.04 should also be on legacy mode since the 'seperate /boot partition' option is grayed out in boot-repair.
I am all out of ideas on what to do. Here is my boot-repair link. The one corresponding to the external should be sdb