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Question
Saturday, June 1, 2019 10:38 PM
A win10 machine here won't boot after a power out last night. Bad BCD it says.
I use Kyhi to boot and get a cmd and try to fix the bcd with bootrec /rebuildbcd
But it doesn't work and says no bcd found and when I do a dir on c:\boot there's no bcd file there.
And it will not create one.
What is the proper procedure in these cases ?
All replies (6)
Saturday, June 1, 2019 10:56 PM
There is no one method that fixes boot failures until a windows bug is fixed.
All steps are on a trial an error basis.
Failure to boot can be due to problems related to:
operating system
registry
boot sector
malware
ransomware
etc.
Using Kyhi you can backup all important files to another disk drive or to the cloud.
Then if necessary perform a clean install.
Other options include:
startup repair
system restore
reset save files
reset save files equivalent
attempt to repair problems related to windows updates
attempt to repair problems related to the boot sector
attempt to repair problems related to the operating system
etc.
Monday, June 3, 2019 2:26 PM
Hi,
For your BCD issue, you could refer to the Boot loader phase section in the following link:
Boot loader phase
/en-us/windows/client-management/advanced-troubleshooting-boot-problems#boot-loader-phase
Hope it could be helpful.
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Wednesday, June 12, 2019 2:02 AM
Hi,
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If no, please reply and tell us the current situation in order to provide further help.
Best Regards，
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Wednesday, June 12, 2019 5:44 AM
There has been a bug in Windows for several builds as per the above post dated:
Saturday, June 1, 2019 10:56 PM
In the link that you posted it was dated:
-
- 2018-11-16
Method 5: Restore System Hive
If Windows cannot load the system registry hive into memory, you must restore the system hive. To do this, use the Windows Recovery Environment or use Emergency Repair Disk (ERD) to copy the files from the C:\Windows\System32\config\RegBack to C:\Windows\System32\config.
If the problem persists, you may want to restore the system state backup to an alternative location, and then retrieve the registry hives to be replaced.
Apparently the authors of the article were unaware of the bug:
https://www.ghacks.net/2018/10/31/windows-10-bug-prevents-registry-backup-creation/
Regback has failed many times for windows 1809, 1803, 1709, etc.
It has not yet been tested in 1903.
Please report the bug so that regback is fixed for 1903 and possibly for older Windows builds.
Wednesday, June 12, 2019 5:52 AM
The location varies depending on which type of Bios you are booting from.
If its a Legacy
IF its a Legacy BIOS-based operating systems. The BCD registry file is located in the C:\Boot\Bcd directory of the active partition. It is a system and hidden file so you may have to enter:
attrib -H -R -S to see it
TRY S:\Boot
Rename BCD BCD.BAK
BCDBOOT c:\Windows /s S: /f SYS
IF its an UEFI–based operating systems. The BCD registry file is located on the EFI ESP system partition.
You have to boot up to a command prompt and type diskpart, then assign letter=S to it.
then change the command prompt from X: to S: by typing S: at the X: prompt
then DIR
There should be a S:\EFI\Boot and a S:\EFI\Microsoft\Boot both have BCD in them?
attrib -H -R -S to see it if you can't see it
Rename BCD BCD.BAK
BCDBOOT c:\Windows /s S: /f SYS
IF BCDBOOT doesn't do the job, BOOTREC /REBUILDBCD
in diskpart: remove letter=S
Wednesday, June 12, 2019 3:22 PM
I've asked this several times over in Reddit, and the feedback is that this bug still exists in 1903.