Windows 10 crashed after update and is now unbootable

A 32-bit Windows 10 1803 installation crashed yesterday afternoon, apparently when an update went awry. Afterwards, attempting to boot results in an Automatic Repair which always fails. I used a recovery command prompt to chkdsk /r /x, which found some corrupted files, and sfc /scannow, which found no problems. Still, it won't boot.

I have tried using restore points from the recovery console command prompt, to no avail. (The restore point fails when restoring the registry, with an error code of 0x80070002.)

Is there any other recourse short of reinstallation? Is Windows 10 really this fragile that a single update can render it unusable?

dalchina said:

Hi, if you're very lucky, if you were to restore the backup copy of the registry which Windows should be automatically creating, you might be able to boot.

Good to know!

However, that could well create an inconsistency between the build state and the registry, perhaps depending on what exactly happened during the course of the failed update (did it change any files).

I was thinking that.

Yes, anything can and will happen and you need to take due precautions, unfortunately. Disks fail, corruption occurs, software isn't perfect, and Windows tries to survive whilst still being a right mishmash of OS and user programs, drivers and files.

This has a brand-new hard drive and a chkdsk run indicates no bad sectors, while sfc reports no problems with system files.

This is one of three PCs which have worked yeoman duty for eleven or so years, and the first time one of them has failed in such a manner. I'm wondering if it's due to the crusty old power supply (which has overheated and sustained damage in the past) not being able to handle the E8500 CPU I installed on the weekend?

System Restore is often commented on here as being problematic and unreliable in restoring.

That is scary.

Disk imaging is something we regard as essential for most users (Macrium reflect (free) + external storage) - and would have helped you in this instance to restore your PC to a previous working state without technical help.

You can't be imaging the disk after before update (which sneak in), can you? And this is the first time in eleven years the machine has failed.

dalchina said:

In any event you create a base image, and differential images (smaller, faster) either manually or on a schedule. That could be daily, weekly- whatever you feel comfortable with.

Interesting but sounds complicated.

It takes just one unfortunate event or combination to render Windows unbootable.

In this case, given that the hard drive was brand new (and remains in good condition), what might have caused this problem? A crash due to the flaky power supply?

For example, my first Win 10 upgrade failed badly- unbootable- because of a particular program I had installed.

I was always able to roll back. Always. And I must have done over a hundred of these over the years, both 32- and 64-bit.

Disk failure does happen- I've been in maybe 10 threads this year where it turned out a drive was failing badly.

Yes, but the disk does not appear to be at fault in this case. Usually they degrade slowly, like the eleven-year-old unit this one (Western Digital Blue 1tb) was replacing. For that matter, the eleven-year-old one still has its image intact, less a few bad sectors. I plan to dd an image file tonight when I get home.

All the files in Regback are zero bytes in length. That nixes that idea.

After using Kyhi boot rescue if you have backed up all of the important files you can perform a clean install and restore the files.
How to Perform a Clean Install or Reinstall of Windows 10 - Microsoft Community

If you want to continue troubleshooting these are steps with a bootable windows 10 iso.

Some of the steps below may repeat earlier steps.
Please use a camera or smartphone camera to take pictures and post images of the commands and images into the thread)

1) Create a bootable Windows 10 iso:
Download Windows 10

2) Power on the computer and click the applicable F Key or temporarily modify the bios boot order to boot to the external USB HD
List of PC brands with their corresponding hot-keys

3) It may take 5 - 10 minutes for the iso to load while viewing the Microsoft Windows icon

4) Select language, time, currency, and keyboard, or click next

5) In the left lower click repair your computer (do not click install)

6) Click troubleshoot

7) Click startup repair (this is expected to fail; if it produces an srttrail.txt file then open file explorer > file > open > find the file > save to the flash drive > later move the drive to another computer and post the srttrail.txt into the thread using a share link (one drive, drop box, google drive)

8) Click system restore (start with the oldest restore point and keep repeating to the most recent restore point) (if all restore points fail or if there are no restore points move to the next step)

9) Click command prompt > this should open a black box with title bar: Administrator: X:\Windows\system32\cmd.exe and prompt: X:\Sources> type these commands (comments will be in partenthesis)

(Use a camera or smart phone camera to take pictures and post images of the commands and the results into the thread)

10) bcdedit /enum
11) bcdedit | find "osdevice"
12) diskpart
13) list disk
14) list volume
15) select disk 0
16) list partition
17) select partition 1
18) detail partition
19) select partition 2
20) detail partition
21) select partition 3
22) detail partition
23) select partition 4
24) detail partition
25) (if there are any additional partition continue in the same fashion)
26) select disk 1
27) detail disk
28) list partition
29) select partition 1
30) detail partition
31) (if there are any additional partitions continue in the same fashion)
32) exit

33) dism /image:M:\ /cleanup-image /revertpendingactions
(replace M with the drive letter for the partition displayed in step #11)
(there is a space between \ and /)

34) (reboot and reopen command prompt if it does not boot to desktop)

35) chkdsk /r M: (change the drive letter M to the partition drive letter from step #11)
(This may take time to complete. If the command is able to proceed it typically will display an ETA)
36) (reboot as necessary)

37) (reopen command prompt)

38) sfc /scannow /offbootdir=M:\ /offwindir=M:\windows
(change the drive letter M to the partition drive letter seen in step # 11)

39) bootrec /fixmbr
40) bootrec /fixboot
41) bootrec /scanos
42) bootrec /rebuildbcd
43) (reboot and reopen command prompt if it does not boot to desktop)

44) C:
45) dir
46) D:
47) dir
48) (view the dir for each drive letter and select the drive letter that has the windows files on the computer.
(The proper drive will display: perflogs, program files, program files (x86), users, windows, etc,)
49) cd \windows\system32\config
50) dir
51) (It should display: bbi, bcd-template, components, default, drivers, elam, sam, security, software, system, vsmidk, journal, regback, systemprofile txr, etc.)
52) (for all steps please use a camera or smart phone camera to take pictures and post images of the commands and the results into the thread)

The comments that were made were in addition those made dalchina so follow the steps that were outlined.
The comments that were made were only if you wanted to try additional troubleshooting steps.
They are command line steps as compared to windows steps.

For the registry backup via task scheduler a computer with windows 1703 displayed 9/26/2018; one with 1803 displayed 9/27/2018 and the one that was upgraded to 1809 displayed: 11/30/1999 (not yet run)

None of these were scheduled.

There were no default settings modified after the upgrade to 1809:




Using Macrium the backup is an extra layer of protection.
Dalchina, what schedule modifications did you make for the computers?
If there is a computer that is not using a backup image what alternative schedule do you recommend?

For what it's worth, I backed up the old hard drive (which had been in use for ten, not eleven, years) using Acronis TrueImage and restored the backup to an SSD.


Using the guide elsewhere on this site, I disabled Automatic Repair on the failing installation and booted it. Windows failed to start, with a 0xC0000225 error code (corrupted registry).

Having established that a corrupted registry was at fault, I installed the SSD (with the restored image) in the machine as the boot drive, leaving the hard drive (with the corrupted installation) installed as a secondary. I booted to Windows 10, navigated to <oldwindir>\system32\config on the hard drive and renamed the five Registry files. I then copied over the five Registry files from <windir>\system32\config (on the restored installation) as replacements for the corrupted files, and rebooted.

Lo and behold, the system booted. I launched System Restore and found that two (no longer five) restore points were available, and selected the oldest one. It is currently restoring the Registry, and hopefully the process will conclude successfully.

I'll post back with the results either way.