Dear Community,
lately I run into trouble updating my Windows 10 laptop:
Hardware: Dell Latitude 5400
OS Version: Windows 10 Enterprise, Version 1909 (Build 18363.1621)
Symptoms:
Auto-Update was enabled and all previous updates installed without issue. Whenever I try to install the cumulative July 2021 update KB5004245, it appears as if the bootloader gets corrputed.
After the required restart, I get a BSOD:
"Recovery
Your PC/Device needs to be repaired
The application or operating system couldn't be loaded because a required file is missing or contains errors.
File: \Windows\system32\winload.efi
Error code: 0xc000007b"
Preliminary Fix
To fix this I booted from Windows 10 installation USB stick and initially followed the instructions from Dell to recover the bootloader ( bootrec /FixBoot) but this results in "Access Denied" message.
Using different instructions based on formatting the boot partition and repairing the bootloader with the command bcdboot successfully fixes the bootloader but the update fails to install.
In the update history i find the error code 0x800f0845
I have also tried to install the 20H2 version instead, but this resulted in similar errors which I was not able to fix and therefore recovered the whole installation from a previous disk image.
Question
Does someone experience similar problems, or may assist me in pinpointing the source of error? Your help is very much appreciated.
Kind regards,
Max
