I removed the original CMOS battery and checked its voltage = 3.00 VDC.
Do I really need to replace the battery?
What sings do show indicate this?

No, the OS on Disk 0 (C:) the one that fails to boot.
I currently running Windows PE OS installed on Disk 2.


I am really sorry about this, but I had 09:00 PM in my local time and was asked to...

Sorry, my bad!

409367

reagentc /info
'reagentc' is not recognized as an internal or external command,
operable program or batch file.

explorer++ is up and running.

Here it is:

bcdedit /store \\?\GLOBALROOT\device\harddisk0\partition1\EFI\Microsoft\Boot\BCD /set {a0a94cac-356a-11ee-9e95-aeb6ae704582} device...

bcdedit /store \\?\GLOBALROOT\device\harddisk0\partition1\EFI\Microsoft\Boot\BCD /set {fwbootmgr} displayorder {7fc884f2-5a91-11e6-8241-806e6f6e6963} /addlast
The operation completed successfully.
...

bcdedit /store \\?\GLOBALROOT\device\harddisk0\partition1\EFI\Microsoft\Boot\BCD /delete {1a04f6db-5a86-11e6-a472-1866da10e8fe}
The operation completed successfully.
bcdedit /store...

Here is the results:

bcdedit /delete {daed529a-5a8e-11e6-be1d-1866da10e8bc}
The boot configuration data store could not be opened.
The system cannot find the file specified.

bcdedit /delete...

I booted successfully as you suggested from a clean W10 installation to a separate external drive.
Please see the attached BCD_Output.txt:
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bcdedit /store \\?\GLOBALROOT\device\harddisk0\partition1\EFI\Microsoft\Boot\BCD:
Windows Boot Manager
--------------------
identifier {bootmgr}
device ...

Here it is:
409248

Disk 0 is Virtual Drive 0.
Disk 1 is Virtual Drive 1.

Shall I proceed with the registry?

Done!

I installed a recovery Windows 10 to a separate drive and booted it.
Now I can see all the virtual drives and their partitions.
Shall I proceed with the registry?

Got it.

I booted from "Windows 10 Pro English (US) 22H2.iso" image and attempted to install W10.
Interestingly, the Windows 10 setup recognized the virtual drives 0 and 1, along with all their...

I booted Windows Recovery Environment (Recovery Mode), CMD, REGEDIT and checked again: no HKEY_LOCAL_MACHINE\Offline hive is not in the list at all...

BCDEDIT responds:
The boot configuration...

Got it!
I managed to export Computer\HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services to the attached file.
408881

I searched the file in a text editor and found a number of suspects:
...

Let me give a try?
What are the steps to begin?

No, it was definitely software, not firmware update.
I managed to boot Sergei Strelec's WinPE from USB and I can see the contents of both OS virtual drive 1 and Data virtual drive 2.
Therefore the...

Greetings!

Windows Version: Windows 10 Pro English (US) 22H2 x64

I was running the OS on a Dell 7910 workstation featuring AVAGO MegaRAID SAS 9361-8i controller loaded with 1 SSD (virtual...