External Hard drive will only boot on one computer

Question

I have an external drive with Linux Mint 18 on it. It boots to my desktop, which is where I used the live CD to install the OS onto the external drive. However, when I try to boot this external drive from my laptop, it will not boot.

Now, I changed the boot menu, made sure I set "Secure Boot" to disabled, and verified that "UEFI boot" is set to enabled, and I still cannot get the drive to boot. I used EasyBCD to install a grub, but that also puts me into the grub menu upon boot. I am not able to see the drive in windows explorer, but it is in the Manage Disks. I tried all of the EasyBCD grub options to no avail.

Am I missing something? I do not want to take a chance and install the grub from the command when it first boots, (I get this message: Minimal BASH-like line editing is supported. For the first word. TAB lists possible command completions. Anywhere else TAB Lists possible device or file complete) because I do not want to take that chance and wipe out my windows boot, or more. When I boot it to my desktop, I get the options from grub asking whether to boot to Linux or Windows.

What am I missing? Can I just add a grub through EasyBCD and if so, which procedure is it? I would like to get this grub on my laptop so that when it boots, I get the option to boot to either Linux or Windows when the drive is plugged in. I want to be able to install this drive to any computer and be able to boot into the Linux OS on this external drive. Even if I have to change the BOIS setting upon boot. That does not bother me.

I was also thinking of just reinstalling the live CD again, only this time, use my laptop to perform the install to "the same" external drive I have Linux Mint 18 on right now. Basically overwriting the OS to the same OS. This way, the grub is on my laptop as well.

However, when I do this, I was thinking about removing the two drives I have in the laptop before installing. My question about this is, "if I do remove the drives, will this work, because I didn't remove the drive from my desktop when I installed the initial OS on the external drive. Does this grub play a role within the C:/? Any help would be greatly appreciated.

Answer 1

UPDATE

The issue occurred because the boot partition was not set on the external hard drive, but was set to the boot partition on the computers boot menu in the bios.

The solution to have an external bootable drive, with any Linux OS and Fedora is to disconnect the drives on the machine you are using. I tested this on from my laptop by installing both Linux Mint 18 and Fedora 25. I used the external hard drive connected through a USB port and installed the OS's of both systems. The external drives now boot when connected to both my laptop and desktop and when they are not connected, the installed OS boots as normal.

In essence, You were correct about the drivers installed were not the drivers to that specific OS on the external drive, but the real issue was the drivers were not on the external drive, but in the BIOS boot menu on the machine.

In short, remove internal drives and then hook up external and boot from CD to install any Linux or Fedora OS. Works now on any machine.

Answer 2

Basically, the installation process installed drivers specific to your desktop onto the external hard drive. It doesn't matter that the hard drive is external. When you try to boot with this external drive connected to your laptop, the hardware drivers installed on the drive are incompatible with the laptop's hardware.

If you want to have a bootable Linux that can be used with more than one computer, you need to boot directly from the live CD (without installing it) and use it as is. You can also create a bootable USB (don't forget to set your BIOS to allow booting from USB).

The only downside to running from a live Linux image is that:

1. If it's a live CD, there is no writable disk space to store files (only limited space mounted in RAM)
2. If it's a live USB stick, there is limited writable disk space on the USB stick itself.

In both cases above, you can always mount the desktop/laptop file system manually once your live Linux is up and running.