Windows 11 23H2 → 25H2 upgrade fails with 0xC1900101-0x40017 during SECOND_BOOT

Heine Rasmussen 20 Reputation points
2026-07-18T18:37:28.2033333+00:00

Windows 11 Pro 23H2 cannot be upgraded to Windows 11 25H2.

The upgrade consistently fails with:

0xC1900101-0x40017

"The installation failed in the SECOND_BOOT phase with an error during BOOT operation."

The installation reaches approximately 75%, reboots, attempts to start the new version and then rolls back to Windows 11 23H2.

The same failure occurs:

  • through Windows Update
  • through the official Microsoft 25H2 ISO using setup.exe and "Keep personal files and apps"

Troubleshooting already performed:

  • SFC completed successfully
  • DISM RestoreHealth completed successfully
  • UEFI enabled
  • Secure Boot enabled
  • No unknown devices in Device Manager

Ran a Farbar scan, with these logs but I have no idea on how to create a fixlist.txt to run

Is anyone able to help?

FRST.txt

Or is there another way to fix my issue?

I'm absolutely stuck on how to fix, and I would like to avoid a clean install

Windows for home | Windows 11 | Windows update
Answer accepted by question author
Ramesh 181.6K Reputation points Volunteer Moderator
2026-07-19T17:13:49.7166667+00:00

Here's the crash info:


SYMBOL_NAME:  FACEIT_AC+191d84

MODULE_NAME: FACEIT_AC

IMAGE_NAME:  FACEIT_AC.sys

STACK_COMMAND: .process /r /p 0xffffd50cf04cb040; .thread /r /p 0xffffd50cf052e1c0 ; kb

BUCKET_ID_FUNC_OFFSET:  191d84

FAILURE_BUCKET_ID:  AV_FACEIT_AC!unknown_function

OSPLATFORM_TYPE:  x64

OSNAME:  Windows 10
Step 1: Unisntall FaceIT AC

The above module belongs to FACEIT AntiCheat.

Please uninstall the respective software.

Step 2: Enable Memory Integrity

Go to Windows Security → Device security → Core isolation details → Memory integrity. Enable the option. If it shows any incompatible drivers, post the screenshot here.

Step 3: Turn off 3rd party services

To avoid third-party software interference, perform a clean boot on the system before running the setup. A clean boot is a process of starting Windows without loading any third-party applications or services. For more information, please refer to the Microsoft article.

How to perform a clean boot in Windows - Microsoft Support

IMPORTANT:

Step 3 in the above link is very important. You need first to enable "Hide all Microsoft Services" before clicking "Disable all".*

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  1. Bikash saha 0 Reputation points
    2026-07-19T18:00:05.0266667+00:00

    <external link removed by Moderator>

    0xC1900101-0x40017 (SECOND_BOOT) is usually caused by an incompatible or outdated driver.

    Try these fixes (short):

    1. Update all drivers (GPU, chipset, storage, network, BIOS).
    2. Uninstall third-party antivirus, VPN, RGB, audio, and hardware utility software.
    3. Open Device Manager → View → Show hidden devices, then uninstall old/greyed-out drivers and restart. This has resolved the error for many users.
    4. Disconnect unnecessary USB devices during the upgrade.

    Run:
    1. Retry the upgrade using the latest Windows 11 25H2 ISO after a clean boot.

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  2. Lucus-V 13,125 Reputation points Microsoft External Staff Moderator
    2026-07-19T16:06:04.5433333+00:00

    Hi Heine Rasmussen,

    Please update all drivers on your system to the latest available versions. In addition, check for any available BIOS updates and install them as well.

    Once these updates have been completed, please try upgrading your system again using the Windows ISO.

    If the issue persists, please feel free to let me know, and I'll be happy to assist you further.

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