Go to Start > Settings > System > Troubleshoot > Other troubleshooters, then run the Windows Update troubleshooter.

 

Hi,

Thank you for your suggestion. I've performed the "Windows Update troubleshooter" step you had mentioned, but I got a message saying that "The Windows Update Diagnostic failed to run". I really don't want to talk to an agent, however.

By the way, the account on the Windows 11 machine is a "Local Account" (I refuse to use an online account for various reasons).

 

Further from my last post (sorry if this is in violation of the forum's rules), I've attached a text file of the "ReportingEvents" log and I have to filter out the logged events back on when the problem started (on September 12, 2025 - that's when it happened).

Please advise if you have any other questions or concerns.

 

The file you attached tells the same story you did in your first post. Here are some steps to take that might correct your issue. I know you have done some of these before but please try them again, and in the order specified.

1. Are you using a third-party anti-malware suite? If so, disable it and go back to Windows Defender.

2. Now, boot into Safe Mode.

Hold the Shift key while clicking Restart from the Power menu, which takes you to the Windows recovery environment. From there, select Troubleshoot > Advanced options > Startup Settings > Restart, then choose Safe Mode with Networking.

3. Run the following commands in order.

DISM /Online /Cleanup-Image /RestoreHealth

SFC /SCANNOW

Now try to update Windows, any success?

4. If not, run the Windows Update Troubleshooter again from safe mode.

Did it complete?

5. If not, clear the Windows Update cache. You may have attempted this already but if you didn't follow certain steps it may not have been successful. Remember that we are still doing this in safe mode too.

Right-click Start and open an Admin Terminal.

Enter the commands

net stop wuauserv
net stop bits

Open File Explorer and navigate to C:\Windows\SoftwareDistribution. Delete all the files and folders inside.
Go back to Command Prompt and restart the services:

net start wuauserv
net start bits

Restart your computer, still in safe mode, and try the update again.

6. If an automatic update fails, try to download and install the update manually from the Microsoft Update Catalog.

Microsoft Update Catalog

Search for "KB5065426".

Find the correct version for your system. For most standard systems it should be the last on the list -- 2025-09 Cumulative Update for Windows 11 Version 24H2 for x64-based Systems (KB5065426) (26100.6584).

Click the Download button, then click the link in the pop-up window to start the download.

Again, while in safe mode, run the downloaded .msu file in the Downloads folder to install the update.

7. If all else fails, perform an in-place repair upgrade.

Download Windows 11

Download Windows 11 Disk Image (ISO)," select Windows 11 (multi-edition ISO) and click Download. Once the ISO file is downloaded, right-click it and select Mount. Open the new virtual drive and run setup.exe. When prompted, choose the option to "Keep personal files and apps" to ensure your data is preserved. Follow the on-screen instructions to complete the installation.

 

Your CBS.log is not compete, so we can't see what is causing the problem. This is not unusual since CBS archives CBS.log entries when the log gets to a certain size.

Please do the following so we can take a look at the archived logs ....

• Open Windows Explorer and browse to the ... C:\Windows\Logs\CBS ... folder.
• Right click on it, and select ... Send to > Compressed (zipped) folder
• A message will appear stating, "Windows cannot create the Compressed (zipped) Folder here. Do you want it to be placed on the desktop instead?"
  • Answer Y to create a folder CBS.zip on your Desktop.
• Please attach it to your next post.
  • If the file is too large, please upload it to a file sharing service and provide the link to it in your next reply.
  • Examples of services to upload to are WeTransfer and TransferKit and SendFileOnline

 

Just so you know, the error code ... 0x800f081f ... indicates that a file or files, and/or the Registry entries in the COMPONENTS hive that reference those files, have been corrupted in some way.

It's one of the most common updating errors.

Fixing it may be easy and quick, but more often it will take time to patch the corruption. Just depends on how much has been corrupted. Sometimes this can be done manually, sometimes a repair install (as suggested by @MPR ) may be the quicker option.