View Full Version : 18.04 Dual Boot with Windows 10. GRUB won't install, need help.

April 27th, 2018, 02:30 PM
Hi Everybody, I am trying to install Ubuntu 18.04 LTS in a dual boot configuration with already installed windows 10 and I am having some issues.

The Problem: I have been trying to install Ubuntu 18.04 LTS Release in dual boot with Windows 10 since this morning but I am having either one of these problems:

1) GRUB won't install, which stops the Ubuntu installation process. I get this error with UEFI selected as first choice in BIOS.

2) It somehow installs but there is no way to boot into it. (GRUB wont show up, no "ubuntu" in BIOS Boot settings.) I get this error with legacy selected as first choice in BIOS.

How I am installing:

create usb boot drive the recommended way from the Ubuntu website.
create empty unallocated partition on windows for 100GB.
Boot via F12 -> choose boot device -> USB -> Install Ubuntu
Create swap partition(8GB) from the free space.
Choose the remaining part of the free space format it in ext4 journaling file system and install.
the device for boot_loader option isn't touched showing the SSD in my device.
Installation continues and I get the error GRUB couldn't be installed.

Any recommendations? Ideal BIOS Settings? What boot order to use?

April 27th, 2018, 02:37 PM
Take a look at my thread which is similar. You will get some info that other members have already offered up. https://ubuntuforums.org/showthread.php?t=2390203

What I would say but I'm a noob so maybe wait for more knowledgable members to chime in is that Windows 10 is probably installed in UEFI mode and you're installing Ubuntu in BIOS mode? The way I installed Ubuntu in UEFI mode was to burn the iso using Etcher from my Mac. Then I hit F12 on the Dell laptop I'm installing on and under UEFI it showed the USB key.

April 27th, 2018, 03:38 PM
If newer UEFI hardware, how you boot install media UEFI or BIOS is then how it installs.
This is for both Windows & Ubuntu.
And UEFI uses gpt partitioning as default and Windows will only boot in UEFI mode from gpt. But if drive was gpt and you install Windows in BIOS mode, it incorrectly converts to MBR(msdos) partitioning.
And then Linux installer gets confused on whether you have MBR or gpt.
BIOS & UEFI Windows partitions, note system has totally different format & meaning between BIOS & UEFI
https://msdn.microsoft.com/en-us/library/windows/hardware/dn898510%28v=vs.85%29.aspx#RecommendedPartitionCon figurations

You really want both systems in same boot mode.
And if newer UEFI hardware, best to use UEFI booting for both installs.

What brand/model system?

New versions of Ubuntu do not use swap partition (unless you already have one) but use a swap file.

April 27th, 2018, 04:41 PM
I took several tries with my two supposedly near identical systems that had been running very happily with a dual-bot of Ubuntu 16.04 LTS and Windows 10 64 pro. I both cases, attempts to install 18.04 resulted in kill the Win 10 boot, and I had to resort to the Win 10 USB stick to recover the Win 10. Then when I did get the 18.04 to load, I had all sorts of problems getting the GRUB to do the right thing. The usual boot-repair disk did not work. One PC needed the final version of 18.04 to give a good install.


August 23rd, 2018, 09:52 PM
What did you have to do to get GRUB to "to the right thing" in the end? THIS is the answer everyone needs.

Also crapped out my windows boot manager but F12 at boot gives it to me. I have 18.04.01 and it updates as it installs. Everything is installed but GRUB.

August 24th, 2018, 12:57 AM
Grub only boots working Windows, or Windows that does not need chkdsk nor is hibernated. And Fast start up is always on hibernation. Even after you turn it off, on a Windows update it will turn it back on, so then use F12 to get into Windows & turn it off again.

Fast Start up off (always on hibernation), note that Windows turns this back on with updates

Boot-Repair usually works, when it does not post the link to the summary report.
And some brands of systems, just want to only boot Windows, so we have multiple work arounds for those systems.