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I have followed this guide to dual boot windows 10 and ubuntu. I have gone through all steps, and succesfully (I think?) installed Ubuntu as described in the end of the linked guide. However, when I restart my computer, it always boots to windows 10.

I have disabled the safe boot, as prescribed in the guide, and I have run the command

bcdedit /set "{bootmgr}" path \EFI\ubuntu\grubx64.efi

in admin powershell, but nothing seems to work. When I restart, I alway just boot to windows 10. I realize many similar questions have been asked here, but none of them have helped me.

nobody
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Richard Jensen
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1 Answers1

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In such case, I would recommend running boot-repair.

https://help.ubuntu.com/community/Boot-Repair

If Ubuntu is indeed installed correctly onto its own partition, boot-repair will find it, along with the other OS (Win10). It will install grub into the boot partition.

Boot-repair can be downloaded and run from a live usb. So using the usb medium you used to install Ubuntu, repeat the procedure to boot your computer from the usb stick, hit "try ubuntu" instead of "install ubuntu" and follow the instructions in the link.

EDIT:

Using the pastebin information you provided, I could tell that 1. Ubuntu seems to be installed on disk, on the same disk as your Windows OS on its own partition. 2. The boot-repair session was run , I presume, from a live session usb booted in legacy mode

Therefore, I suspect your problems arise from having installed Ubuntu from a legacy mode booted usb. This won't work well with Windows 10, which in standard configuration always is EFI booted.

The work around you described tries to alter this, by forcing Win10 to boot in CSM/Legacy. But I advice the other way around: re-installing Ubuntu in EFI.

Steps: 1. Boot into BIOS. Make sure every usb device is EFI booted
2. Boot from ubuntu live usb, confirm EFI boot.
3. Re-install ubuntu in sda6 partition
(4. If needed, re-run boot repair from a EFI booted live usb)

user172056
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  • I have just tried that. With the software I use, it didn't work (it couldn't find the correct iso file, and when I forced it to use it, the boot just went to grey screen).

    I tried using rufus too. Here it seemed to boot correctly, but when I ran the boot-repair, I got an error message telling me something along the lines that I was using a legacy, uhm, something. I can do it again if you want more specific error message.

     – Richard Jensen Mar 12 '20 at 16:38
  • And here's the pastebin of the boot-repair if that's of any use. – Richard Jensen Mar 12 '20 at 16:46
  • I have editted my answer based on your input. – user172056 Mar 13 '20 at 12:39
  • UEFI and BIOS/Legacy/CSM boot modes are not compatible. Best to convert Ubuntu to UEFI boot mode. And you can use Boot-Repair in UEFI boot mode and using its advanced mode uninstall grub's BIOS version and reinstall grub's UEFI version. Best not to use really old info like installing 14.04. See these: https://help.ubuntu.com/community/UEFI Also shows Windows 10 screens or similar to Windows 8 https://askubuntu.com/questions/221835/installing-ubuntu-on-a-pre-installed-windows-10-with-uefi – oldfred Mar 13 '20 at 13:51
  • Comment above is in line with my answer – user172056 Mar 16 '20 at 14:37