I have spent a few days and can't seem to find a clear answer for this.
Goal: Install Ubuntu onto a USB 3 flash drive (not Live/Persistent) FOR my Surface Pro WITHOUT touching any of my Surface Pro partitions.
So when I first attempt to install Ubuntu (12.04), the installer did not bother asking me where I want to install the bootloader, I assume it automatically wrote over my Surface Pro EFI boot because after I rebooted without the flash drive (where I installed my Ubuntu to) attached I'm greeted with "Grub Minimal Bash like System", so it basically couldn't find where Grub was installed to. I was still able to get into Windows through Grub when I have my Ubuntu USB attached so I can access grub's Windows 8 entry. But this is NOT want I want. I prefer not to have USB in at all if I want to boot into windows.
After hours of searching for a resolution to this, I ended up wiping my Surface Pro completely because no one seems to be able to explain UEFI boot other than the fact it's "different than BIOS".
After restoring everything, upgrading back to Windows 8.1, I'm making a second attempt at this and same thing happens when I create my own partitions on the Flash Drive, it still seems to just overwrite the default bootloader.
First Question: How can I restore the default bootloader so it would boot directly into Windows 8?
Second Question: How can I install Grub on the flash drive so that whenever I want to boot into Ubuntu I would use this workflow: Boot to Windows -> PC Settings -> Advanced Restart -> Reboot from Media/USB/CD Devices -> Boot from my Ubuntu USB
Any help would be greatly appreciated.
P.S I tried Ubuntu 13.10 livecd and it would not boot on my surface pro.