Update to 25H2

Error 0xc1900101 usually indicates conflict with network adapters, storage controllers, display drivers and additionally the external devices. Open the device manager and make sure that all of your drivers are up-to-date. There should be no drivers present with warning symbol.

Additionally I recommend to disconnect external devices and temporarily disable third-party security software while performing the upgrade.

Let us know if this helps!

Hello

23H2 reached end of life in Nov 2025. When a version has reached EoL, it means you will not be able to update from Settings anymore.

Usually if the gap is 2 version or less, you may or may not be able to run an inplace upgrade using the installation assistant.

I would suggest that you run the PC Health Check App first to make sure your computer is still meeting requirements.

https://support.microsoft.com/windows/how-to-use-the-pc-health-check-app-9c8abd9b-03ba-4e67-81ef-36f37caa7844

If it does meet requirements, you can go here:

https://www.microsoft.com/software-download/windows11

Download the installation assistant tool, and run it and upgrade it from there.

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If the installation tool won't upgrade it, you would need to consider a clean install as the gap is too big. You do need to backup your files first.

The following steps should be done on a working Windows computer:

Download the Windows Media Creation Tool from Microsoft's official website. https://www.microsoft.com/software-download/windows11 click on the "download now" button under "Create Windows 11 Installation Media"

Run the tool and select "Create installation media for another PC."

Choose "USB flash drive" as the media to use for the installation and select "Next."

Connect a USB flash drive with at least 8 GB of free space to your computer.

Select the USB flash drive you want to use, and then select "Next."

The tool will then download the required files and create the installation media.

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Now these steps will  be done on your problematic computer:

Go to the computer's BIOS boot menu to have it boot from the USB drive.

Follow the on-screen instructions to install Windows 11, making sure to choose "Custom install" and select the option to delete all existing partitions.

Once the installation is complete, you'll have a clean installation of Windows 11 on your computer.

Error 0xC1900101 during an upgrade to Windows 11 25H2 is classified as a driver-related upgrade failure. Since free disk space and basic driver updates are already in place and the issue occurs on multiple devices, a deeper cleanup and repair sequence is required.

Use the following steps on each PC before retrying the 25H2 upgrade:

1. Confirm space and Windows Update status
   1. Ensure at least 20 GB of free space on the system drive for a 64-bit OS.
   2. Open Settings > Windows Update and install all pending updates (including optional driver and cumulative updates). Run Windows Update more than once until nothing new is offered.
   3. If Windows Update itself has problems, run the Windows Update troubleshooter as described in the Windows 11 section under Run Windows Update a few times and Windows Update Troubleshooter.
2. Disconnect all nonessential hardware
   1. Physically unplug external drives, USB sticks, docks, printers, and any other peripherals that are not strictly needed (leave only keyboard, mouse, display, and network if required).
3. Check Device Manager for problematic drivers
   1. In the taskbar search box, type device manager and open Device Manager.
   2. Expand each category and look for devices marked with a yellow exclamation icon.
   3. For each such device, right‑click it and choose Update Driver Software or Uninstall to resolve the issue.
   4. If a device is uninstalled, restart and let Windows reinstall its driver automatically, or install the latest driver from the hardware manufacturer.
4. Remove third‑party security software
   1. Uninstall any non‑Microsoft antivirus, antispyware, or security suites from both machines.
   2. Keep any product keys and installers so they can be reinstalled after the upgrade.
   3. During this period, protection is provided by Windows Defender (Windows Security).
5. Repair disk errors
   1. Open Command Prompt as administrator.
   2. Run:

            chkdsk /f C:
      

   3. Approve the prompt to schedule the scan, then restart the PC so the disk check and repair can run.
6. Repair system image and core system files
   1. After the disk check completes and Windows has started, open Command Prompt as administrator again.
   2. Run:

            DISM.exe /Online /Cleanup-image /Restorehealth
      

   3. Wait for the operation to finish; this repairs the Windows image used for servicing and upgrades.
7. Perform a clean boot and retry the 25H2 upgrade
   1. Configure a clean boot so that only essential Microsoft services and minimal startup items run. Follow the steps in How to perform a clean boot in Windows.
   2. Restart into this clean-boot environment.
   3. Try the 25H2 upgrade again:
      • Preferably via Windows Update; or
      • If Windows Update continues to fail, perform an in‑place upgrade using a Windows 11 ISO as described in the 25H2 and in‑place upgrade guidance from the context.
8. If 0xC1900101 persists
   1. At this point, the remaining cause is typically a specific third‑party driver or low‑level software (e.g., storage, RAID, or security drivers) that is still blocking setup.
   2. Use the guidance under Resolve Windows upgrade errors from the same documentation set to analyze setup logs and identify the exact driver or component causing the rollback.

This sequence aligns with the documented remediation steps for 0xC1900101 (driver) upgrade errors on Windows 11 and has been used in similar 23H2→25H2 upgrade failure scenarios.

References:

• Get help with Windows upgrade and installation errors
• Troubleshoot problems updating Windows
• Lenovo T14S Gen 4 cannot upgrade from 23H2 to 25H2 - Microsoft Q&A
• How to install 25H2 enablement package? - Microsoft Q&A