Ambiguous Windows Boot Loader Volume Path

Hi all.

I have a question I wish to get an answer to, eagerly.

I have a dual-boot machine. It has two Windows 11 installations, both of which are version 24H2 build 26100.1742. This machine is partly incompatible with Windows 11 system requirements.

When in msconfig, I see the two Windows 11 installations. One Windows 11 installation is on M.2 NVMe drive (installed first place and upgraded from Windows 10 up to Windows 11 24H2 in 5 years), the other Windows 11 installation is on SATA drive (installed second place and upgraded from Windows 11 23H2 up to 24H2).

Windows 11 on M.2 NVMe drive has boot files path (\Device\HarddiskVolume3\WINDOWS), which is EFI system partition (100 MB) on M.2 NVMe drive and is the expected partition. This is seen from the attached screenshot of msconfig when msconfig is run from Windows 11 on SATA drive.



Windows 11 on SATA drive has boot files path (\Device\HarddiskVolume10\Windows), which is Data drive Q: (Volume10), as can be seen from msconfig screenshot taken when Windows 11 is running on M.2 NVMe drive.



I expected this path should have been (\Device\HarddiskVolume3) or (\Device\HarddiskVolume8). HarddiskVolume3 is the EFI system volume of first-installed Windows 11 on NVMe drive. HarddiskVolume8 is EFI system volume of second-installed Windows 11 on SATA drive. But instead of HarddiskVolume3 or HarddiskVolume8, the path surprisingly indicates HarddiskVolume10, the Q: data drive. This I find strange.



Both Windows installations boot up fine. They know their boot paths precisely. But why Windows 11 Boot Loader on SATA drive points to Q: drive, HarddiskVolume10, is a mystery to me. How does Q: drive (HarddiskVolume10) come into the equation of this dual-boot scenario ? Can it be because volume numbering may be different while system is booting up as opposed to when volume numbering is obtained in fully-booted Windows 11.

I have just one Windows Boot Manager, which is on Crucial M.2 NVMe drive as can be seen from the related BIOS screenshots.



By the way, Windows Boot Manager is on Volume1 of NVMe drive, the Windows partition.



If I disable the SATA drive known as Q: drive (volume10) in BIOS, do I lose bootability to Windows 11 on SATA drive (volume6) ?

If I run "bcdboot W:\Windows" after I assign letter W to the Windows 11 partition on SATA drive when Windows 11 is running on NVMe drive, can I correct the volume numbering of Windows 11 on SATA drive ?

Or should I run "bcdboot W:\Windows /s S: /f UEFI" after I assign letter W to Windows partition on SATA drive and letter S to EFI system partition on NVMe drive ?

Has any of you observed such a bizarre (to me, anyway) situation before ?

What can the more knowledgeable guys here in this reputable forum suggest I should do ?

I repeat both Windows 11 installations on their own drives boot up just fine. So no problems thus far. I can choose which Windows 11 I should boot to using "Sysdm.cpl -> Advanced tab -> Startup and Recovery -> Settings -> Dropdown menu of Default Operating System"



This is the Disk Management screenshot:



I hope I provided enough information.

suatcini54 said:

Windows 11 installation is on M.2 NVMe drive (installed first place

Click to expand...

I can tell you the why of it but would not venture to instruct you how to fix it. If you want to change your language to English, expand the columns of disk management so all can be seen, and post another screenshot, others here might feel comfortable doing so.

Here's the why. The OS install process will always create an EFI partition to hold its boot configuration data on the first UEFI disk that uefi bios SEES. and that will not always be the disk where BCD should be. It is for this reason one should always disconnect additional drives when installing an OS or at least temporarily disable extra drives in bios. In the case of your m.2 , bios saw that disk first and installed it's BCD into the appropriate EFI partition because (1)either only one disk was installed at the time of install OR (2)your mobo bios prioritizes m.2 disk numbering over hdd.

But for most OEM boards that is not usually the case. Example, in my Dell bios recognizes the sata drives first and assigns lower disk numbers to them. My sata storage drives are disk 0 and 1. My boot m.2 is disk 2. When I installed Windows, I disconnected the 2 stata drives, making bios number my m.2 as disk 0 during the install so that's where it put its BCD.

Thank you @glasskuter for your response. As I said in my post, my system runs perfectly. Therefore, I will wait for some other answers along with yours and then adventure to disable the Q: drive in BIOS to see what will happen. Maybe, the Windows on SATA drive will find another volume to populate its boot configuration files on and continue its existence happily ever after there. Regards

suatcini54 said:

Maybe, the Windows on SATA drive will find another volume to populate its boot configuration files on and continue its existence happily ever after there.

Click to expand...

No it won't. Once BCD is written to a given efi partition, it's not going to magically move on its own.

glasskuter said:

No it won't. Once BCD is written to a given efi partition, it's not going to magically move on its own.

Click to expand...

Thanks. Q: drive does not have an EFI partition on it. It is simply a data drive in GPT partition table format. That was why I was curious. If BCD cannot be moved, that means Windows on SATA drive will be unbootable once I disable the Q: drive in BIOS. I will advise when I do that.

I'm sure there are folks that can help you rebuild BCD. I'm just not comfortable being one of them.

Thanks glasskuter for your reply.

I disabled Volume10 (Q: drive) in BIOS and restarted. My PC had a hard time to reboot to the other Windows 11 even though it was the default OS because Volume numbers changed. Another data drive assumed Volume10. But I still had the dual-boot capability. Then I re-enabled Q: drive in BIOS and restarted. This time I got a BSOD.



I restarted one more time and everything has become the same as before I started the experiment. Q: drive is assigned back Volume10.