Lenovo T14S Gen 4 cannot upgrade from 23H2 to 25H2

The most successful method to install version 25H2 is to use the Windows 11 ISO.

The 25H2 update requires at least 40GB of free space on the C drive, because the old Windows system is transferred into the Windows.old folder on the C drive, then 8GB is required for the download and more space is required for temporary files.

Please ensure you download the ISO in the same language as you use for the Windows UI, follow the steps, this is then not like re-installing Windows, it is just like an update and your personal files, settings and installed software will not be affected.

Click this link:

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

to download the Windows 11 ISO

When the ISO file completes downloading

Disconnect from the Internet

Disconnect all external devices with the exception of a mouse or keyboard.

Temporarily disable any 3rd party Anti-virus you may have installed

Then, in Windows File Explorer, double click the ISO and then run Setup.exe and select the Install option.

Very Important - ensure you select the option to keep your files and apps.

Follow these steps to troubleshoot the rollback from 23H2 to 25H2 on the Lenovo T14s Gen 4:

1. Free up more disk space
   • 20 GB is the minimum for a 64-bit OS upgrade. Increase free space on C: to well above 20 GB (for example 30–40 GB) by removing temporary files and unused apps. See the guidance in Free up drive space in Windows referenced under 0xC1900101 errors.
2. Remove third‑party update and driver tools
   • Uninstall Norton Driver Updater and any other third‑party “driver updater” utilities. These tools can install incompatible drivers that cause rollback during feature updates.
   • After uninstalling, restart the PC.
3. Update drivers and firmware only from Lenovo and Windows Update
   • Run Lenovo System Update again and install all critical/BIOS/chipset/storage/display updates.
   • Then run Windows Update repeatedly until no further updates (including optional driver updates) are offered.
4. Temporarily reduce third‑party security impact
   • In Norton 360, disable features that block or filter Windows Update during the upgrade (for example, aggressive firewall or update‑blocking features).
   • If problems persist, temporarily uninstall Norton 360 before attempting the upgrade again, then reinstall it after the system is successfully on 25H2.
5. Try an in‑place upgrade using ISO media
   • If Windows Update keeps rolling back, perform an in‑place upgrade using the latest Windows 11 ISO, as described in the in‑place upgrade steps in the Dutch answer in context:
     • Download the latest Windows 11 multi‑edition ISO from the Microsoft Software Download page.
     • Mount the ISO, run Setup.exe.
     • On the first screen, choose to change how Setup downloads updates and select “Not now” to reduce variables.
     • Choose to keep personal files and apps.
     • Start the installation and let it complete; the PC will restart several times.
6. If the upgrade still rolls back
   • Check for specific error codes in Settings → Windows Update → Update history.
   • For 0xC1900101‑style errors (driver‑related), follow the driver guidance in the Windows 11 upgrade error article: ensure enough space, run Windows Update multiple times, update third‑party drivers from the manufacturer, and unplug non‑essential external hardware during the upgrade.

If these steps fail and a specific error code appears (for example 0xC1900101, 0x80070002, 0x800F0818, 0x800F0922), use that code with the troubleshooting articles in the references to narrow down the cause.

References:

• Get help with Windows upgrade and installation errors
• Windows 11, version 23H2 update history
• Mijn windows updates gaan mis - Microsoft Q&A
• I am getting an error when trying to upgrade to Win 11. Error 0x80070002[gle=0x0000007f] - Microsoft Q&A
• 2025-10 Cumulative Update for Windows 11 Version 23H2 for x64-based Systems (KB5066793) Install error - 0x800f0922 - Microsoft Q&A