Inaccessible boot device

bromberg · 18 Jul 2019

Suddenly, I cannot boot my Windows 10 Pro (v1903).
I was fine with the new upgrade to version 1903 for a couple of weeks but for reasons I cannot determine, I am now getting the error message: INACCESSIBLE BOOT DEVICE.
I got into the repair menu and through DOS I issued a bootrec.exe /fixboot command but received an ACCESS IS DENIED error message.
I used my one and only restore point and was able to get back up. But when I rebooted the same INACCESSIBLE BOOT DEVICE message reappeared and now I have no restore points to work with (so a lesson to you all: check whether Windows is creating more than one!).

Also, I tried the usual chkdsk & sfc commands which (as usual) were useless.

Thanks in advance for any suggestions.
Danny

Ztruker · 18 Jul 2019

Your post does not belong in this forum. As the bright yellow header says:

I'll ask @Brink to move this to General Support | Windows 10 Forums

zbook · 19 Jul 2019

1) What are the status of the computer files?
a) files backed up to another disk drive
b) backup image on another disk drive
c) files not backed up and need to be saved
d) files not backed up and can be deleted

2) Find two flash drives you can format (> or = 8 GB)

3) Find a camera or smartphone camera so that you can take pictures and post images into the thead.

4) When posting images they can be uploaded:

How to Upload and Post Screenshots and Files at Ten Forums

5) In case there are any probems posting images please use share links (one drive, drop box, or google drive)

Error - Office.com

2) On a working computer create a bootable windows 10 iso:

https://www.microsoft.com/en-us/soft...load/windows10
Download Windows 10 ISO File

3) On a working computer create a bootable Ubuntu / Linux flash drive:

Download Windows 10 ISO File

Linux to the rescue! How Ubuntu can help a computer in distress | PCWorld

4) Using Ubuntu backup all important files to another disk drive

5) Test the drive using HD Sentinel Linux:

Hard Disk Sentinel - Free Linux version

Post images of the tab results using share links (one drive, drop box, or google drive)

6) Once files are backed up you can
a) clean install
b) reset save files equivalent
c) troubleshoot: all steps are trial and error (there are multiple causes for this bugcheck 7B). (Some can or cannot be fixed using Windows RE)

7) Boot using the Windows 10 iso:

List of PC brands with their corresponding hot-keys

If necessary temporarily change the BIOS boot order so the eternal USB HD is on top.

8) Open the Windows advanced troubleshooting menu on the iso

9) click command prompt > this should open a black box with title bar: Administrator: X:\Windows\System32\cmd.exe and prompt: X:\Sources>

10) Type these commands. (Comments are in parenthesis).

11) bcedit /enum
12) bcdedit | find "osdevice"
(note the partition drive letter)

c:
dir
d:
dir
e:
dir

diskpart
lis dis
lis vol
sel dis 0
det dis
lis par
sel par 1
det par
sel par 2
det par
sel par 3
det par
sel par 4
det par
sel par 5
det par
sel par 6
det par
sel dis 1
det dis
lis vol
lis par
sel par 1
det par
(post images into the thread)
exit

Dism /Image:W:\ /Get-Packages

(change the drive letter W: to the partition drive letter displayed running the bcdedit command)
(look for any rows displaying: state: install pending or state: uninstall pending)

dism /Image:W:\ /Cleanup-Image /RevertPendingActions
(change the drive letter W: to the partition drive letter displayed running the bcdedit commands)

(Reboot)

(Find the package(s) that were just installed by date).
(Run the following command on the last installed package.)
(example):
dism.exe /image:W:\ /remove-package /packagename:Package_for_KB4014329~31bf3856ad364e35~amd64~~10.0.1.0
(change the drive letter W: to the partition drive letter displayed running the bcdedit commands)

(Reboot)

(repeat remove-packages multiple times as necessary to uninstall any windows updates in the past few days)

chkdsk W: /r /v
(change the drive letter W: to the partition drive letter displayed running the bcdedit command)
(This may take many hours and typically displays ETA)
(Reboot to run the command).

(More troublesooting steps to follow).

bromberg · 19 Jul 2019

Zbook:

Will the bootable flash drive give me the exact same Windows 10 functionality with all my apps executing as a normal boot would, or would I be limited as in SAFE MODE?

However, I'm not sure the BIOS of my Lenovo M81 desktop allows me to boot from a flash drive, so I'll have to check on that.

In any case, thank you for your detailed suggestion and apologies for posting this in th BSOD forum, but I thought this might be considered a BSOD (at least the background was blue

and thought it was the best place to post it.

Dan

zbook · 19 Jul 2019

There is a windows advanced troubleshooting menu on the computer and another on a bootable windows 10 iso.
They are similar.
The computer has startup options that are not on the iso.
For example safe mode when working is only on the computer menu.

Using the windows advanced troubleshooting menu on the iso should offer options for:
startup repair
system restore
command prompt
etc.

Most of the troubleshooting steps are performed using command prompt:
remove recent windows updates
check for drive file system corruption and repair
repair the boot sector
repair the operating system
repair the registry
perform a reset save files equivalent
perform a clean install
etc.

There may be some modifications needed but most computers can boot from a flash drive.

Inaccessible boot device is bugcheck 7B.
It cannot be debugged like most bugchecks.

Once you back up files and test the drive you have more flexibility.

FreeBooter · 19 Jul 2019

Please boot your computer with Windows Setup Media and from Windows Recovery Environment start the Command Prompt.

Please type below commands into Command Prompt and press Enter key.

Following commands will repair Master Boot Record (MBR), Boot Sector and BCD Store.

Code:

Bootrec /FixMbr

Bootrec  /FixBoot

Bootrec /scanos

Bootrec  /RebuildBcd

zbook · 19 Jul 2019

The OP had access denied for fixboot.

FreeBooter · 19 Jul 2019

Master boot record could be corrupted also EFI partition could be damaged.

If Windows 10 installed HDD missing a EFI System Reserved partition you can create one by following below instructions.

Please boot your computer with Windows Installation Media and from Windows Recovery Environment start the Command Prompt.

From Command Prompt execute below commands one at a time:

Code:

Diskpart

List Disk 

Select Disk 0

List Partition

Select Partition X

Shrink desired=100

Create Partition EFI

FORMAT FS=FAT32 LABEL="ESP"

Assign Letter=W

Exit

 bcdboot C:\Windows /s W: /f  ALL

Use "List Disk" command to find out disk number assign to Windows 10 installed drive.

Replace number 0 zero with disk number assign to Windows 10 installed drive

Use "List Partition" command to find out Windows 10 installed partition assigned number.

Replace X letter with Windows 10 installed partition assigned number.

You may need to replace C: drive letter with Windows 10 installed partition drive letter.

I have to warn you Diskpart tool is very dangers so please make sure to execute Diskpart command carefully.

farrellart · 19 Jul 2019

FreeBooter said:

Please boot your computer with Windows Setup Media and from Windows Recovery Environment start the Command Prompt.

Please type below commands into Command Prompt and press Enter key.

Following commands will repair Master Boot Record (MBR), Boot Sector and BCD Store.

Code:

Bootrec /FixMbr

Bootrec  /FixBoot

Bootrec /scanos

Bootrec  /RebuildBcd

Seconded!!

Try Bootrec.exe /FixMbr
then Bootrec.exe /FixBoot from the command prompt off the recovery disk/usb.

bromberg · 19 Jul 2019

I've tried the bootrec's 'fixmbr' and 'rebuildbcd' commands successfully and 'fixboot' unsuccessfully (access denied error).
Since I have no restore points available and I'm prevented from repairing my boot record (BTW, how can I tell if my boot record is even damaged and if I need to worry about repairing it?), if I create a Windows bootup disk will I be able to boot into my HDD and use all of Windows or will I be limited in functionality?

Thanks, Dan