Dear Steve Hertel,
Thank you for reaching out to the Microsoft Q&A Forum.
Before diving into specific fixes, let's confirm the computer officially meets the requirements for Windows 11. This helps rule out fundamental hardware incompatibility as a root cause for update failures and instability. You can refer to this Windows 11 Specs and System Requirements | Microsoft Windows
If your device meets all these requirements, you could try manually installing from Microsoft Update Catalog:
- Go to Microsoft Update Catalog.
- Search for KB5070773.
- Download the correct version for Windows 11 Version 25H2 for x64-based system. It will be an .msu file.
- Run the downloaded .msu file to install the update.
If still failing, you can also try performing an In-place Upgrade. Please read this Reinstall Windows with the installation media - Microsoft Support
Disclaimer: Let's try performing an in-place install or in-place upgrade which will refresh your Windows files and operating system without removing files or applications. That being said, we always recommend that if you have important data, you should back up it up before making large system changes. If you want to back up your data first, please do so.
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