(1) BitDefender isn't made by Microsoft. It isn't even offered in the MS Store. I guess it is a legit 3rd-party behemoth that means to take Windows Defender's place. But I don't think you need it. I suggest you pursue the effort to fully uninstall it & let Windows Defender reactivate. That's all you need. But I'm unsure BitDefender is causing the current problem(s) since you aren't reporting any alerts. But maybe it is. You haven't answered: Does Windows Defender think it is activated or does it know BitDefender is in charge at "Click Defender in Tray, Virus & Threat Protection, Manage Settings"? But pursue BitDefender's full removal.
(2) Every time you post a List Vol, it looks a bit different. Can't you unplug all those extraneous HDD until this problem is over? Just leave Disk 0 plugged & any other internal HDD that is difficult to get at. Then, show us...
DiskPart <<<Enter DiskPart
List Vol <<<List the volumes & letters
List Disk <<<List the disks
Select Disk 0 <<<Focus on Disk 0
List Part <<<List its partitions
Select Disk 1 <<<Focus on Disk 1
List Part <<<List its partitions
== Continue to select & list each disk that showed up in List Disk. ==
== ==
== Then, put a letter back onto the EFI partition. It likely still looks like ==
== Volume 3 NO NAME FAT32 Partition 100 MB Healthy System ==
Select Vol 3 <<<That presumes EFI still is Vol 3
Assign Letter=Y <<<Give it letter Y -- (I wonder how it went away)
Exit <<<Exit DiskPart
BCDEdit /Store Y:\EFI\Microsoft\Boot\BCD /Enum All
BCDEdit /Enum {fwbootmgr} <<<Show Firmware Boot Manager
BCDEdit <<<Show Windows Boot Manager & Boot Loader(s)
When you use "/Store", BCDEdit won't have to find the BCD on its own. So, maybe the error message won't happen & we'll see it. But try the other two (without /Store) also now that extraneous drives are unplugged. Maybe they will magically work too now. And what does MSInfo32 now say is your Boot Device? The last it said was ... 10. I think it needs to say ... 2 to be using the EFI that is on Disk 0.
(3) Continue with Ramesh to make a Macrium system image. Then, use that article he recommended to fix your EFI. I think that should work although you get no MSR & EFI will remain the 2nd partition.
(4) But, if you want the partitions where they normally would be, then I think this does it...
(a) Shrink C: by 116 MB (Disk Management can do that).
(b) Slide C: rightward fully past the 116 MB (3rd-party software is needed).
(c) After that, the following would create an EFI & MSR where they belong. This certainly will not work while booted to Windows. I think you should boot to an external recovery environment to do this, not the internal one (Shift+Restart) ...
DiskPart <<<Enter DiskPart
Select Disk 0 <<<Focus on Disk 0
List Part <<<Show its partitions
Partition ### Type Size Offset
------------- ---------- -------- ---------
Partition 1 Primary 930 GB 1024 KB
Partition 2 System 100 MB 930 GB <<<Current EFI
Partition 3 Primary 589 MB 930 GB
Select Part 2 <<<Focus on current EFI
Delete Partition Override <<<Delete it
Create Partition EFI Size=100 <<<Make a new EFI partition
Format Quick FS=Fat32 Label="System" <<<Format it
Assign Letter="S" <<<Give it letter S
Create Partition MSR Size=16 <<<Create MSR of 16 MB
List Part <<<Should see EFI & MSR at front now
List Vol <<<Show volumes & letters
Exit <<<Leave DiskPart
== Examine the List Vol to see what letter is on the Windows partition. ==
== Use it in the following BCDBoot command instead of C (if different). ==
== Volume 1 C BOOT DISK C NTFS Partition 930 GB Healthy Boot ==
BCDBoot C:\Windows /s S: /f UEFI <<<Populate new EFI -- not necessarily C:.
Reboot hopefully to a functioning Windows.
Definitely have a Macium system image available in case of problems. And know how to restore it.
Those "create partition" commands should each start looking from the beginning of Disk 0 for the 1st instance of the amount of space specified & deposit the new EFI (100 MB) & MSR (16 MB) partitions into it. I hope that will work. Good luck.