Win11Pro changes UEFI boot order -- on its own

NavyLCDR · Dec 10, 2023

trumpy81 said:
You are still relying on Windows BCD to do the selecting.

Remove the Windows Boot Manager and then try selecting the drive to boot to, without resorting to manual manipulation and without entering your BIOS.

See how far you get then.

This post makes it very clear that you have no idea what you are talking about.

trumpy81 · Dec 10, 2023

Remove the following lines from the BCD and then try to switch drives after rebooting.

partition=\Device\HarddiskVolume10
partition=\Device\HarddiskVolume11

These addresses replace the drive letters in case you were wondering, read the BCD outputs you posted.

SIW2 · Dec 10, 2023

The info is stored in bcd as
PartEx and HD sig

windows will display that to you in user friendly form if you run bcdedit. It will show you an alias either a letter or a device path.

Similarly, you are not expected to know those long numbers so bcdedit will accept commands you use with a letter or device path and translates them into the real information as above.

Bootmgr reads what is in the bcd store so it knows on which disk and partition to find winload.

trumpy81 · Dec 10, 2023

Exactly and without the Boot Control Data (BCD) you have nothing, so Windows would not even boot.

Remove the bootloaders and you have no way of switching OS/drives.

Windows needs to have something to tell it where to find the OS.

NavyLCDR · Dec 10, 2023

trumpy81 said:
Exactly and without the Boot Control Data (BCD) you have nothing, so Windows would not even boot.

Remove the bootloaders and you have no way of switching OS/drives.

Windows needs to have something to tell it where to find the OS.

At boot time, though, it is not drive letters that tells the boot loader where to find Windows. Drive letters do not get assigned until Windows load. All drive letters are simply mount points. Drive letters do not exist until Windows loads and assigns them. The Windows Boot Manager does not assign drive letters - the Windows OS does.

trumpy81 · Dec 10, 2023

Then why does the BCD have this:
device partition=D:
path \Windows\system32\winload.efi

Does that not tell Windows where to find the OS?

And is that not changed when dual boot is setup in the usual manner?

Windows Boot Manager (BCD) does the directing. Windows does the changing.

NavyLCDR · Dec 10, 2023

Because the bcdedit command looks in the Windows registry to determine what drive letter is assigned to the location of the partition contained in the BCD and substitutes it to make it human friendly. You have failed to explain why there are no drive letters assigned to the BCD I posted:

Code:

S:\EFI\Microsoft\Boot>bcdedit /store BCD

Windows Boot Manager
--------------------
identifier              {bootmgr}
device                  partition=S:
path                    \EFI\Microsoft\Boot\bootmgfw.efi
description             Windows Boot Manager
locale                  en-US
inherit                 {globalsettings}
default                 {default}
resumeobject            {3cbfc69b-8bc7-11ee-b2b0-84e9f6fdd286}
displayorder            {default}
                        {3cbfc698-8bc7-11ee-b2b0-84e9f6fdd286}
toolsdisplayorder       {memdiag}
timeout                 30

Windows Boot Loader
-------------------
identifier              {default}
device                  partition=\Device\HarddiskVolume11
path                    \Windows\system32\winload.efi
description             Windows 10
locale                  en-US
inherit                 {bootloadersettings}
isolatedcontext         Yes
allowedinmemorysettings 0x15000075
osdevice                partition=\Device\HarddiskVolume11
systemroot              \Windows
resumeobject            {3cbfc69b-8bc7-11ee-b2b0-84e9f6fdd286}
nx                      OptIn
bootmenupolicy          Standard

Windows Boot Loader
-------------------
identifier              {3cbfc698-8bc7-11ee-b2b0-84e9f6fdd286}
device                  partition=\Device\HarddiskVolume10
path                    \Windows\system32\winload.efi
description             Windows 11
locale                  en-US
inherit                 {bootloadersettings}
isolatedcontext         Yes
allowedinmemorysettings 0x15000075
osdevice                partition=\Device\HarddiskVolume10
systemroot              \Windows
resumeobject            {3cbfc697-8bc7-11ee-b2b0-84e9f6fdd286}
nx                      OptIn
bootmenupolicy          Standard

S:\EFI\Microsoft\Boot>

The BCD tells the Windows Boot Manager that the Windows installation identified as the default {default} is located at \Device\HarddiskVolume11. There is no drive letter assigned to \Device\HarddiskVolume11 until Windows loads. Similarly, the BCD tells the Windows Boot Manager that the Windows installation identified as {3cbfc698-8bc7-11ee-b2b0-84e9f6fdd286} is located at \Device\HarddiskVolume10. There is no drive letter assigned to \Device\HarddiskVolume10 until Windows loads.

If I run BCDEDIT on the same BCD from a Windows installation that has assigned a drive letter to \Device\HarddiskVolume11, then it will substitute that drive letter in place of \Device\HarddiskVolume11. However, since I ran BCDEDIT from a Windows installation that had not assigned a drive letter to \Device\HarddiskVolume11, it displays it as \Device\HarddiskVolume11. The drive letter is not stored in the BCD. The drive letter assigned to it is stored in the Windows registry.

SIW2 · Dec 10, 2023

Read my previous post.

bcd stores PartEx and HD sig. Windows will display that to you in user friendly form if you run bcdedit. It finds the relevant letter ( if there is one ) which relates to that disk/partition by looking in the mounted devices key in the currently running os and shows that to you .

That is why if I run bcdedit when booted into the os on the third partition it shows the fifth partition on this disk as E. Because the mounted devices key in the os registry on partition 3 shows the fifth partition as E

But if I run bcdedit after booting into the os on the fifth partition, it displays as C. Because the mounted devices key in the os registry on partition five shows the fifth partition as C

NavyLCDR · Dec 11, 2023

The Windows Boot Manager does not assign drive letters. Drive letters are not contained in the BCD. It is the Windows OS that assigns drive letters based upon the information contained in the registry at Computer\HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices

trumpy81 · Dec 11, 2023

SIW2 said:
That is why if I run bcdedit when booted into the os on the third partition it shows the fifth partition on this disk as E

but if I run bcdedit after booting into the os on the fifth partition, it displays as C

And that is exactly what I have been saying all along.

The Windows Boot Manager (BCD) is what directs Windows to the boot drive/path of the OS loader (winload.efi).

NavyLCDR · Dec 11, 2023

trumpy81 said:
And that is exactly what I have been saying all along.

The Windows Boot Manager (BCD) is what directs Windows to the boot drive/path of the OS loader (winload.efi).

In post #22 you posted, "When you boot from more than one OS, the Windows Boot Manager will reassign the selected drive and name it C:\ regardless of what the actual drive letter was."

That post is incorrect. Period. The Windows Boot Manager does not assign, nor reassign drive letters. And I posted multiple examples that proved it is an incorrect statement.

trumpy81 · Dec 11, 2023

Why do I bother.

Have it your way, I'm out.

NavyLCDR · Dec 11, 2023

trumpy81 said:
Why do I bother.

Have it your way, I'm out.

Thank goodness, don't let the door hit you on the.....

trumpy81 · Dec 11, 2023

trumpy81 said:
The first link in the chain is the Windows Boot Manager. It signals Windows as to which drive etc. is selected, Windows then makes the necessary changes.

No Windows Boot Manager = no drive selected = Windows selects the default drive.

My wording was a little ambiguous, but I was not trying to explain the overall operations, just trying to make things digestible.

I hope that is clear enough for you?

I guess you missed this post?

NavyLCDR · Dec 11, 2023

trumpy81 said:
I guess you missed this post?

You lied. You said you were out. You certainly are "trumpy", I'll give you that.

SIW2 · Dec 11, 2023

You have been mistaken all along. Why is that a problem ? There are lots of things I don't know.

POLYSIUS · Dec 11, 2023

When egoshooter hijack a thread you never get a result. 77 replies and not a single answer to the problem Mark Phelps has.

With a simple trick you get the BCD result the Navyman posted. Before you give an answer, make sure that you understand the problem.

Mark Phelps · Dec 14, 2023

POLYSIUS said:
When egoshooter hijack a thread you never get a result. 77 replies and not a single answer to the problem Mark Phelps has.

...

Thanks for the observation ... and it is still doing it, so much so that installed EFI Editor on all the OSs and use that to be able FORCE the boot list to have rEFInd as the first entry before I exit any of the OSs. I thought that would fix the issue, but it did not because even though I have verified the boot order before exiting Win11, after I do restart , I still get the BSOD due to invalid first boot entry.

At first, I thought Ithat Windows 10 was doing it because when I restarted from inside Win10, I got the problem. But no sooner had I determined that then restarting from Win11 Pro started giving me the same issues -- but restarting from inside Win10 brought up the rEFInd menu. But not ALL the time! Only SOME of the time! I've since been unable to determine any useful pattern to this.

Quite by accident, the Del key (to force UEFI Setting entry) started working again -- so I can use that to boot into UEFI settings to change the boot order to prevent the BSOD from coming up by default.

But again, the list order gets changed without my intervention -- still to this day.

kiefozaur · Mar 1, 2024

Mark Phelps said:
Thanks for the observation ... and it is still doing it, so much so that installed EFI Editor on all the OSs and use that to be able FORCE the boot list to have rEFInd as the first entry before I exit any of the OSs. I thought that would fix the issue, but it did not because even though I have verified the boot order before exiting Win11, after I do restart , I still get the BSOD due to invalid first boot entry.

At first, I thought Ithat Windows 10 was doing it because when I restarted from inside Win10, I got the problem. But no sooner had I determined that then restarting from Win11 Pro started giving me the same issues -- but restarting from inside Win10 brought up the rEFInd menu. But not ALL the time! Only SOME of the time! I've since been unable to determine any useful pattern to this.

Quite by accident, the Del key (to force UEFI Setting entry) started working again -- so I can use that to boot into UEFI settings to change the boot order to prevent the BSOD from coming up by default.

But again, the list order gets changed without my intervention -- still to this day.

Hi,
IDK if you solved your problem... anyway I stumbled upon the same issue - Windows 11 reverting UEFI boot order assigned in Linux (Pop!_OS). Got three OSs Linux Pop!_OS, Windows 11 Pro, Windows 10 Pro
Solution which worked for me:

In Windows 11 run Command Line as Administrator then:

to save backup of current settings:

Code:

bcdedit /export "<full path>\<file name>.bcd" (e.g. bcdedit /export "E:\Backups\BootManager_22_02_2024.bcd")

to mount ESP/EFI partition:

Code:

mountvol <drive letter>: /S (e.g. mountvol X: /S)

to check if refind directory is present:

Code:

dir <drive letter>:\EFI (e.g. dir X:\EFI\)

if not:

Code:

xcopy /E <path to your bootloader>\* <drive letter>:\EFI\<bootloader>\* (e.g. xcopy /E D:\refind-bin-0.14.0.2\refind\* X:\EFI\refind\*)

assuming you use x64 architecture remove all driver and tool directories as well as boot files except *_x64 and config:

Code:

PowerShell.exe -Command "&{Remove-Item <drive letter>:\EFI\refind\* "-Exclude *_x64*,*.conf-sample" -Recurse -Confirm:$false}" (e.g. PowerShell.exe -Command "&{Remove-Item X:\EFI\refind\* "-Exclude *_x64*,*.conf-sample" -Recurse -Confirm:$false}"

rename refind.conf-sample to refind.conf:

Code:

ren <drive letter>:\EFI\refind\refind.conf-sample refind.conf (e.g. ren X:\EFI\refind\refind.conf-sample refind.conf)

and finally set boot manager to load:

Code:

bcdedit /set "{bootmgr}" description "rEFInd Boot Manager" path \EFI\refind\refind_x64.efi

Restart PC

If it's working I would suggest to backup BCD for easy restore in case of NVRAM reset or major Windows update which can mangle boot order:

Code:

 bcdedit /export "<path to file>" (e.g. bcdedit /export "D:\BCD_refind_backup.bcd")

Code:

 bcdedit /import "<path to file>" (e.g. bcdedit /import "D:\BCD_refind_backup.bcd")

Win11Pro changes UEFI boot order -- on its own

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