Cannot install Windows 11 updates – error 0x800f0991 on ASUS ZenBook Pro 14 Duo OLED

To address the update error 0x800f0991 on your ASUS ZenBook Pro 14 Duo OLED running Windows 11, here are some steps you can take:

1. Check for Windows Update Corruptions: Since you have already run SFC and DISM, ensure that your Windows Update components are not corrupted. You can use the DISM tool again with the following command:

      DISM.exe /Online /Cleanup-image /Restorehealth
   

   This command will check for and repair any corruptions in the Windows image.
2. Manual Update Installation: Unfortunately, I cannot provide a direct link to manually download the required update files for OS build 26200.6899 as it is not available in the provided context. However, you can check the official Microsoft Update Catalog website for the specific update related to your OS build.
3. Advanced Repair Steps: If the above steps do not resolve the issue, consider the following:
   • Reset Windows Update Components: You can reset the Windows Update components manually by stopping the Windows Update service, deleting the SoftwareDistribution folder, and then restarting the service. Here’s how:
     1. Open Command Prompt as Administrator.
     2. Run the following commands one by one:

                net stop wuauserv
                net stop cryptSvc
                net stop bits
                net stop msiserver
                del %windir%\SoftwareDistribution /f /s /q
                net start wuauserv
                net start cryptSvc
                net start bits
                net start msiserver
        

   • Perform an In-Place Upgrade: This will reinstall Windows while keeping your files and applications intact. You can do this by downloading the Windows 11 installation media from the Microsoft website and selecting the option to upgrade your PC.
4. Contact Support: If none of these solutions work, consider reaching out to Microsoft Support for further assistance.

These steps should help you troubleshoot and potentially resolve the update error you are encountering.

References:

• Resolved issues in Windows 11, version 24H2
• Fix Windows Update corruptions and installation failures

Hi, good day!

• What specific update are you trying to install?
• Have you tried manually downloading and installing updates from the Microsoft Update Catalog?

I recommend performing a repair installation via Settings or using the Windows 11 ISO.

Open Settings > System > Recovery.

Few things to check on the PC

• Unplug all external peripherals except for the Mouse, Keyboard, and LAN cable before starting
• Disable or uninstall any third-party Antivirus program to prevent it from interfering with the upgrade

Under Fix problems using Windows Update, click Reinstall Now

Once completed, your system will restart.

Alternatively, you can use the Windows 11 ISO by following the steps in the link below.

https://v4.hkg1.meaqua.org/en-us/answers/questions/4252110/how-to-run-in-place-upgrade-in-windows-11?forum=windows-all&referrer=answers

I look forward to receiving your update and I'm willing to collaborate with you till we resolve the issue. Do keep me informed by clicking "Add comment" below.