Recovering FDE Ubuntu/Grub after (re-)installing Windows

Asked by Aaron Whitehouse on 2016-05-15

Hi,

How do I repair/recover my Grub after reinstalling Windows 7 if my Ubuntu (16.04) had full-disk encryption enabled?

I'm an Ubuntu user but kept Windows around as a dual-boot. I had it set up as people normally do, with the Grub screen coming up and Ubuntu booting by default, but with Windows as an option. I recently went into Windows to test out relative performance of a game. I was updating the AMD graphics driver in Windows when the machine crashed, leaving the driver half-installed. The Windows machine then failed to boot. To fix that, I reinstalled Windows.

Unfortunately, reinstalling Windows overwrote Grub and it just booted into Windows without the ability to boot into Ubuntu. I tried following:
https://help.ubuntu.com/community/RecoveringUbuntuAfterInstallingWindows
There were no special instructions for FDE installs, so I just set up a boot-repair boot disk and did the "Recommended Repair". That didn't do anything. I went back in and decrypted the FDE disk first, then ran the tool. No joy. I then tried to make some sensible guesses on the advanced options. Still no luck.

I can obviously reinstall Ubuntu on the machine to fix this, but I hope there is a better way. If there is, I would also like to update that help page to help others stuck in this situation, so I thought I'd ask.

Question information

Language:
English Edit question
Status:
Solved
For:
Ubuntu grub Edit question
Assignee:
No assignee Edit question
Solved by:
Aaron Whitehouse
Solved:
2016-05-15
Last query:
2016-05-15
Last reply:
2016-05-15
Manfred Hampl (m-hampl) said : #1

Maybe you can use the commands from http://www.omgubuntu.co.uk/2011/09/live-usb-sticking-grub-2-video after decrypting the hard disk.

Okay, I got a lot further when I was connected to the internet, as it gave me a bunch of additional commands. Now I have Grub back (I have other problems, but I'll ask about those elsewhere).

Thanks!