boot options disappear after installing windows in UEFI mode?

Question

I have ubuntu 19.10 on my system with the Legacy boot. I installed Windows 10 in UEFI mode and now boot options are missing at the startup.

I tried the following approaches to fix the bootloader so far:

• tried boot-repair utility, it failed with following error: 'Please enable a repository containing the [grub-efi-amd64-signed] packages'
• created UEFI partition and tried installing grub on it manually. It also didn't work.
• logged into windows and tried easyBCD utility. Here in add new entry option, Linux is disabled.

But neither worked. I cannot log in to Ubuntu now. However, I have bootable Ubuntu USB handy with me, /home is on a separate partition.

is there a way to fix the boot loader without losing any data? If re-install is the only option, If I use the re-install ubuntu option instead of "something-else" will it fix the bootloader?

Solution 1

You have to use the 19.10 live image when you use BootRepair to fix 19.10.

I've also seen this on Ubuntu when people use a live disk of a different version to be repaired. Also, many people have reported this error with the using the Boot Repair disk on other distros. The thing is, Boot Repair complains about the missing repo of the installed version, not the version of the live image.

Solution 2

As suggeted by @mchild in the comments, you need to use correct version of Ubuntu live image. If it doesn't work follow below steps to fix the issue.

You can enable to boot into both UEFI and Legacy BIOS from firmware settings. Many computers with UEFI firmware will allow you to enable a legacy BIOS compatibility mode. In this mode, the UEFI firmware functions as a standard BIOS instead of UEFI firmware.

However, I recommend reinstalling Ubuntu as UEFI.

Uninstall Ubuntu

1. Make a backup of your /home first. Even if it is in a separate partition, make a backup. You may need to delete this partition too as you may run into issues with MBR and GPT as Ubuntu was installed from Legacy BIOS. But you can have a try without changing it...
2. To uninstall Ubuntu, boot into Windows and delete your Ubuntu partitions (They will not have a file system name).
3. If you are planning to install Ubuntu using Something else option leave the free space as it is. If you will use the Install alongside Windows option, extend the Windows partition so that it takes up the free space too.
4. Repair Windows boot loader. See How to Repair Windows Bootloader Problems for instructions.

This will also help How to Uninstall a Linux Dual-Boot System From Your Computer

Install Ubuntu

This is really straightforward really. You have already installed Ubuntu once so you know how it is done.

1. This time just do what you did before but make sure that UEFI is the only boot option enabled in Firmware settings.
2. Boot into your bootable USB but make sure you boot into the UEFI version. There may be two (these may have different names. Look for one that starts with UEFI-).
3. If you have booted into UEFI you will see the Install alongside Windows option. If you can see this you can either chose it or chose the Something else option. If you don't see it you haven't selected the UEFI option.
4. Make sure that after installing, Ubuntu is 1st in boot sequence in firmware options.

Solution 3

Your Windows 10 is installed in UEFI mode (non CSM) with GPT partitioning. (And your Ubuntu was installed in UEFI (CSM[legacy]). They are both different and that's why not working side by side.

1. Change your boot settings from BIOS to UEFI Only (Non CSM).
2. Make a bootable USB using Rufus
   • Choose partitioning scheme to GPT
   • Choose boot mode to UEFI Only (Non CSM)
3. Boot from USB
4. Install Ubuntu

Comments

[mchid]

The boot repair error happens sometimes when you use a live image of a different Ubuntu version. Are you using a 19.10 live image?

[Govinda Sakhare]

@mchid No. I am using latest live image of Ubuntu i.e. 20.04. I also tried with boot-repair-disk and got the same error.

[mchid]

I think you should use the 19.10 live image. I've also seen this on Ubuntu when people use a live disk of a different version to be repaired. Also, many people have reported this error with the using the Boot Repair disk on other distros. The thing is that Boot Repair complains about the missing repo of the installed version, not the version of the live image.

[oldfred]

The only real difference between an UEFI install of Ubuntu and BIOS/CSM/Legacy install is the version of grub2, the few settings are automatically changed when you reinstall the correct version of grub. So in Ubuntu Live installer, you just need to be sure to boot in UEFI mode and run Boot-Repair to install the UEFI version of grub or grub-efi-amd64.efi. You can reinstall but must always boot flash drives & computer in UEFI mode. Shows installer with screen shots. Both BIOS purple accessibility screen & UEFI black grub menu screen help.ubuntu.com/community/UEFI

[Govinda Sakhare]

@mchid using right version of live image worked. Do you want to post an answer? so that I can give you due credits :)

[VidathD]

You better award the bounty. Or else it will be wasted. No one will get it and you won't get it back.

[Govinda Sakhare]

@mchid suggestions helped me, so wait for him to post the answer. If he doesn't, then I will award it you.

[mchid]

@GovindaSakhare I will post it as an answer

[Govinda Sakhare]

home is on a separate partition. So that's not an issue.

[VidathD]

@GovindaSakhare No. You will have to uninstall Ubuntu and install it again. See here how to uninstall Ubuntu howtogeek.com/141818/…. Proceed only if you can see the install alongside windows option (you can choose something else option if you can see the install alongside windows option). Make sure only UEFI boot mode is enabled in firmware settings before you install. Select the boot option of your USB that starts with UEFI -. Rest is the same process as you used before to install in Legacy BIOS.

[Govinda Sakhare]

My home partition is different, I can mount it again. so don't think I will lose any data.

[VidathD]

@GovindaSakhare Answer updated.

[VidathD]

@GovindaSakhare If this helped you please accept the question and award the bounty.

[Govinda Sakhare]

I haven't tried it yet. Will try it on Friday, Saturday,

[WinEunuuchs2Unix]

@GovindaSakhare Today is Sunday and bounty expires in 12 hours...