2026-02 Preview Update (KB5077241) (26200.7922) Install error - 0x800f0991

Question

I've tried to pause updates, command prompts and still I'm failing.

Answer 1

Hi Amy,

I understand that you’ve been attempting to install the latest Windows Insider update, but you’re still seeing error 0x800f0991 despite trying several troubleshooting steps.

As a next step, please check whether the “Fix problems using Windows Update” option is available on your device. You can find this under Settings > System > Recovery. This option repairs the Windows update components while keeping your apps, files, and settings intact, and it has helped many Insider users resolve similar update issues.

If that option isn’t available on your build or if the update still fails afterward, the most reliable next step would be an in‑place upgrade using the Windows 11 ISO. This refreshes the system files and update engine without removing personal data and is the recommended recovery approach for persistent update errors on Insider builds:

-Go to the official Windows 11 download page and download the Windows 11 ISO that matches your current edition and language.

-Once the download completes, right‑click the ISO file and select Mount.

-Open the mounted drive and double‑click setup.exe.

-On the Ready to install screen, make sure “Keep Windows settings, personal files, and apps” is selected, then choose Install.

-Allow the process to complete. Your device will restart during the upgrade, and your files and applications should remain unchanged.

-After the upgrade finishes, return to Settings > Windows Update > Windows Insider Program and check for updates again.

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 it up before making large system changes. If you want to back up your data first, please do so.

Please let me know how it goes, and I’ll be happy to help if you need anything further.

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