Upgrading To 14.04 LTS (Trusty Tahr) Blew Up Grub

Question

I used the upgrade option available at the Ubuntu store from the desktop. There was an option within the software updates to upgrade to 14.04 LTS (Trusty Tahr). After I employed this to upgrade, Ubuntu will not boot and I'm at the grub rescue prompt just after the bios screen. I do not make it to the Ubuntu splash screen.

I researched a bit and now have a bootable thumb drive that I would like to boot to after pressing the F9 key. I then would like to use the portable (thumb-drive/CD) OS to fix my grub issue, so that I can boot up normally and begin enjoying Ubuntu 14.04 LTS (Trusty Tahr).

My questions are the following. Am I on the correct path to fixing my issue? And also, how can I fix the GRUB OS loader using my portable OS (that is on my thumb-drive)?

I would be grateful for any information that would lead to a solution regarding my issue.

Answer 1

Am on the correct path to fixing my issue?

Yes. It's possible reinstalling GRUB to the MBR won't fix the problem, but most likely it will, and it's the place to start.

how can I fix the GRUB OS loader using my portable OS (that is on my thumb-drive)?

What you want to do is usually called "repairing GRUB" or "reinstalling GRUB to the MBR." (It's called these things because it usually achieves the first, and it consists largely of the second.)

There are several techniques for this. Any should work. But if one does not, you can try another.

Some are detailed in How can I repair grub? (How to get Ubuntu back after installing Windows?). While your problem was not caused by a recent Windows installation, the solutions there will still likely fix it. (The parenthesized part of the title is an example of when repairing GRUB is needed, but there are other cases, like this one.)

• I'd suggest trying with the Boot-Repair utility. (More information on that here.)

Another good resource is the Fixing a Broken System section of Grub2/Installing.