[Solved] Windows 10 UEFI Boot Issue: Access Denied on Bootrec /fixboot, and Unsuccessful BCD Rebuild

Hello.
I have had a problem starting my computer since yesterday. Trying to boot the system back to the bios. I have tried various actions with bcdboot and bootrec and it still has problems

I run the installation of windows 1803 (I have a flash drive with this version of build), go to the console and have the following symptoms:

Bootrec / fixmbr - correct operation
Bootrec / fixboot - Access denied
Bootrec / scanos - finds one windows installation [D]
Bootrec / rebuildbcd - finds one widnows installation and it doesn't matter if we choose [Y] or [N] or All, I get the following message: Unable to find the requested system device.

Disk configuration (per diskpart)
list disk:
Disk 0 Online 1863GB 0
Disk 1 Online 476GB 0 GPT *
Disk 2 Online 14GB 0
Disk 3 No media

letter part:
Disk 0
partition 1 - primary 1863GB

Disk 1
partition 1 - recovery 450GB
partition 2 - system 100MB
Partition 3 - Reserved 16MB
Partition 4 - primary 467GB

Windows 10 is installed on partition 4 - but I can't run it
Please help

The easiest way is to disable UEFI in BIOS and then install the system.

Automatic repair with Startup Repair Tool
MBR repair
Command 1: bootrec.exe / fixmbr
Command 2: bootsect.exe / nt60 all / mbr

boot sector repair
Command 1: bootrec.exe / fixboot
Command 2: bootsect / nt60 C: (repair partition c
Command 3: bootsect / nt60 SYS (repair system partition)
Command 4: bootsect / nt60 ALL (repair all partitions

reconstruction of the BCD warehouse
Command: bootrec.exe / rebuildbcd

I would also, to simplify the situation as much as possible, disconnect "Disk 0" and then take all these repair options (and maybe even start them by checking whether the system will not be able to cope with the system without using commands from the console).

unfortunately it does not boot without disk 0

To enter all these commands you must have a system CD. You set up boot from disc, boot the computer, click any key, and then you enter the recovery console and enter the commands I gave one by one.

system board?
Not enough pendrive with installer?
I also tried auto repair and it was not successful

Pendrive can also be.

Andrzej Ch. wrote:

unfortunately it does not boot without disk 0

What is not starting? Lest it immediately turn out that the system and boot were separated and now there is nothing to fix.

@Matuzalem
I have a boot flash drive made with the Win 10 build 1803 installer (made with Microsoft's system image download tool) exactly as installed. Can I use it to try to repair from the admin console mode.
Do I understand correctly?
What does it mean "system and boot separated"?

So if the system does not boot without disk 0, it means that this disk has a boot sector and this disk needs to be repaired.

I followed the instructions given by my colleague @krzychupar

Below I will list only those that turned out to be wrong:
bootsect / nt60 all / mbr- for drive F: parameter invalid - unable to open root directory
\ Device \ HarddiskVolume5 - The parameter is invalid - cannot open root directory

\ ?? \ PhisycalDrive1
Bootcode is only updated on MBR. Different partitioning scheme is used on this disk

bootsect / nt60 SYS - target volumes will be updated with BOOTMGR compatible bootcode
The system partition not found - The specified system device could not be found

Bootsect / nt60 ALL
D: (\\ Volume {xxxxxxxxxxxxxxxxxx} Updated filesystem bootcode. The update may unreliable the volume could not be locked during update. Access denied.
F: (\\ Volume {xxxxxxxxxxxxxxxxxx} cannot open root directory. Invalid parameter
\ Device \ HarddiskVolume5 - The parameter is invalid - cannot open root directory

After that, I started my computer. It is unchanged. The system does not start, after about 10 sec. uefi bios opens.


One more first symptom that something is wrong were blue screens with the information "Inaccesible boot device" and now it doesn't even have such a message, it just goes to the bios right away

Please give me further advice. I want to run windows from this drive. The new installation is not taken into account.


If I turn off the UEFI mode in the motherboard's BIOS, then the system tries to boot, but I get the error: "Inaccesible boot device"
When I turn on UEFI again for about 1/2 sec. I will flash blue screen of death with error 0xc0000001.
I don't know what to do next?

I get alternating blue screens with errors:
-inaccesible boot device
- error 0xc0000001


I can see that no one can help, which is a pity, now I fixed the errors and problems with the inaccesible boot device myself. There was only one problem left for me, that is repairing (replacing, etc.) the file on the boot partition:
EFI \ Microsoft \ boot \ resources \ custom \ bootres.dll.
When you try to boot the system, information about the corruption of this file is written to the srttrail.txt file.

It remains to reinstall the system from scratch.