Problem Installin Dual Boot with Win 10

[Teksonik]

Hello, I am getting the following message when trying to install 20.04 dual booted with Win 10: "Executing 'grub-install/dev/sda' Failed. This is a Fatal Error".

Now Win 10 won't boot either giving an invalid boot device error.

Anyone have any ideas how to proceed ? I could just install over Win 10 and give Kubuntu the whole drive but I have some programs I'd like to keep on the Win side.

I'm creating a Win 10 Recovery USB now to see if I can repair the damage but even if it works I'll still need to get past the Kubuntu install error.

Thanks in advance for any assistance!

[oshunluvr]

Hard to say why grub install failed since the installer doesn't really give you a usable error message.

The usual way to proceed is to boot back to the Kubuntu USB and choose "Try...". Then open a terminal and manually attempt to install GRUB to your hard drive (it may not be /dev/sda after reboot so you need to verify the device name before attempting this). This will give you a chance to see the actual error message. Since you're using Windows 10, it's using EFI and GPT. GRUB shouldn't have a problem with that. You need to have "secure boot" disabled in your BIOS.

Assuming drive device name is sda, the grub installation command is

sudo grub-install /dev/sda

If it proceeds without error, then run

sudo update-grub

and you should be good to reboot. If it has an error when attempting installation, post the exact error message. Phone pic is OK

[Teksonik]

Thanks I get the error message of "grub-install: error: failed to get canonical path of '/cow' . "

[jlittle]

Are you clear on the difference between UEFI and BIOS/MBR? On some motherboards it's very easy to boot a USB in the wrong one. When you boot from the USB, there may be more than one choice.

Win 10 normally installs with UEFI, but the computer conceivably could have been upgraded from Win 7, and thus be BIOS/MBR.

[oshunluvr]

I believe that error occurs when a destination needed for files isn't found and mounted. Assuming EFI, it may not be finding your EFI partition.

Run this command and post the results:

sudo gdisk -l /dev/sda


Assuming there is indeed an EFI partition, there is a grub install switch to force it:

--efi-directory=/dev/sda3

Normally GRUB locates this EFI partition by the partition type. It may not be set right. Or as jlittle suggests we might be dealing with a mixed environment.

[mr_raider]

If it's a UEFI install I sugegst using refind:

https://www.rodsbooks.com/refind/getting.html

Make a USB out of the iso, then plug it in and boot from it. Refind will allow you to directly boot windows, or Linux and bypass the bootloader by selecting the kernel.

[Teksonik]

Thanks for the help everyone. I tried to fix the Win 10 install with a restore USB but it failed. Attempting to install Linux dual boot damaged a partition but I was able to back up the files using the Linux Live USB. So I just went ahead and installed Kubuntu by itself. I hated to lose the Win 10 Pro license but it wasn't my main system and I've got four other systems running Win 10. I've dual booted Win and Linux on at least a half dozen other systems but this was the first time I've had any issues. It's always worked perfectly in the past.

So everything is working fine now. It's amazing how much faster Kubuntu is on the same system than Win 10 was, it's really gotten to be a pig in recent years. Thanks again for all the help.

[mr_raider]

Thanks for the help everyone. I tried to fix the Win 10 install with a restore USB but it failed. Attempting to install Linux dual boot damaged a partition but I was able to back up the files using the Linux Live USB. So I just went ahead and installed Kubuntu by itself. I hated to lose the Win 10 Pro license but it wasn't my main system and I've got four other systems running Win 10. I've dual booted Win and Linux on at least a half dozen other systems but this was the first time I've had any issues. It's always worked perfectly in the past.

So everything is working fine now. It's amazing how much faster Kubuntu is on the same system than Win 10 was, it's really gotten to be a pig in recent years. Thanks again for all the help.

your license is not lost. It's attached to your hotmail/outlook.com account.

[Teksonik]

All my Win 10 licenses are attached to the same Outlook account.

Just to clarify, obviously that Win 10 license is locked to this machine. I've already installed Kubuntu and am loving it so have no plans to take it back to Win 10.