0

I am attempting to dual boot Ubuntu and Windows 10. I want to use Windows Boot Manager, and not GRUB. I already have Windows 10 booting in UEFI mode. I have 32 gigabytes of unallocated space to install Ubuntu on, but after I finish the installation, I don't want the boot order to be changed. I will then add Ubuntu to Windows Boot Manager by running bcdedit /set "{bootmgr}" path \EFI\ubuntu\grubx64.efi. How can I make sure that the boot order isn't changed while installing Ubuntu?

name
  • 26
  • 1
  • Can't you just change it back after installation? – u1686_grawity Sep 24 '21 at 08:08
  • Do you mean letting Ubuntu become the default OS, going into the BIOS and changing the default OS back to Windows Boot Manager, then adding Ubuntu to Windows Boot Manager? I think that would work, but it would be better if the first two steps could be skipped. Does the "Something else" partition option when installing Ubuntu set Ubuntu as the default OS? (sorry if that question shouldn't be in the comments) – name Sep 24 '21 at 09:05
  • You don't need to add Ubuntu to the Windows Boot Manager, the UEFI boot menu is enough and Ubuntu will just add itself to that menu. UEFI works differently from GRUB. Ensure you're using an EFI installation media for Ubuntu. – harrymc Sep 24 '21 at 09:13
  • Is the UEFI boot menu the one that the "bcdedit" command changes? If so, then every time I have said Windows Boot Manager I have meant the UEFI boot menu. Does it automatically add Ubuntu to the UEFI menu if you choose the "Something else" partition option? – name Sep 24 '21 at 09:35
  • @name: I mean letting Ubuntu become the default OS, then using `efibootmgr --bootorder 000x` from within Ubuntu to make the Windows Boot Manager go first. (Though note that your plan to run Ubuntu _from_ Windows Boot Manager is likely to fail in EFI; some say it works, but in my experience Bootmgr refuses to launch GRUB.) – u1686_grawity Sep 24 '21 at 09:42
  • @name: The "bcdedit" command deals with _both_ the UEFI boot menu and the Windows Boot Manager menu. Specifically, `{fwbootmgr}` represents UEFI boot menu as a whole (and its 'displayorder' corresponds to efibootmgr's --bootorder), `{bootmgr}` represents the specific UEFI boot menu item that _launches_ Windows Boot Manager, and `{current}` represents the specific menu item within Windows Boot Manager that launches Windows itself. See also `bcdedit /enum firmware` for all entries within the UEFI Menu, and `bcdedit /enum bootapp` for entries within the Windows Boot Manager menu. – u1686_grawity Sep 24 '21 at 09:46
  • @name: So since you're actually editing the UEFI boot menu via {bootmgr}, it really confuses me a bit, because by doing so you'd be _replacing the Windows boot entry_ and would no longer be able to boot into Windows (i.e. the UEFI entry that says "Windows Boot Manager" would launch Ubuntu...) and that seems like it kinda defeats the point of your question about making sure Windows remains first... It seems like you want to create a _new_ entry using `bcdedit /create`, but then you get the same result as with just letting Ubuntu create its entry and swapping the order. – u1686_grawity Sep 24 '21 at 09:48
  • I got the command from https://superuser.com/questions/1471937/how-can-i-add-a-bcd-boot-entry-for-linux-in-windows-boot-manager-in-efi. After looking at other commands, maybe it should be bcdboot \EFI\ubuntu\grubx64.efi. The result I am aiming for is shown here: https://i.stack.imgur.com/yh7VC.png Does the "Something else" partition option do that automatically? – name Sep 25 '21 at 04:05

0 Answers0