Arch Linux

diederick76

Member

Registered: 2010-02-14

Posts: 157

Windows 10 removes Grub entry in boot order [SOLVED]

After installing a base arch, I installed and configured Grub to have an extra entry for booting Windows 10, but after I rebooted into Windows, the boot order in my firmware had changed and the Grub menu no longer appeared. On https://wiki.archlinux.org/index.php/Un … boot_order there are some suggestions to handle this, but they are not really clear to me.

If the previous steps do not work, you can tell the Windows boot loader to run a different UEFI application. From a Windows Administrator command prompt:

# bcdedit /set "{bootmgr}" path "\EFI\path\to\app.efi"

What different UEFI application could I run here? When I run bcdedit /enum firmware from a Windows command prompt, I can see \EFI\GRUB\grubx64.efi but it is on a different disk from the one Windows is on (both have an EFI partition - is that the correct way?) so how do I refer to grubx64.efi here?

Alternatively, you can set a startup script in Windows that ensures that the boot order is set correctly every time you boot Windows.

1.   Open a command prompt with admin privlages. Run bcdedit /enum firmware and find your desired boot entry.
2.   Copy the Identifier, including the brackets, e.g. {31d0d5f4-22ad-11e5-b30b-806e6f6e6963}
3.   Create a batch file with the command bcdedit /set "{fwbootmgr}" DEFAULT "{copied boot identifier}"
4.   Open gpedit.msc and under Local Computer Policy > Computer Configuration > Windows Settings > Scripts(Startup/Shutdown), choose Startup
5.   Under the Scripts tab, choose the Add button, and select your batch file

When I open the command prompt with admin privileges, I am in C:\Windows\system32. After step 3 there is no .BAT-file added to that directory. Where is the batch file I just created and what is its name?

Last edited by diederick76 (2018-04-29 15:08:13)

diederick76

Member

Registered: 2010-02-14

Posts: 157

Re: Windows 10 removes Grub entry in boot order [SOLVED]

So, it appears that the command

bcdedit /set "{fwbootmgr}" DEFAULT "{copied boot identifier}

does not in fact create the batch file, but one has to create a batch file and put that command in. In retrospect, I can see how the author of the sentence will have meant that. Apart from the fact that gpedit.msc is not by default available in my Windows 10 installation, the solution worked and I'm marking this as solved.