Problem with failed update

Question

2025-09 Cumulative Update for Windows 11 Version 24H2 for x64-based Systems (KB5065426) (26100.6584)

Failed to install on ‎10/‎09/‎2025 - 0x800f0845

Computer hangs on boot up. I can only boot up by restarting.

Win Update checking says computer is up to date

I cannot reinstall this update as the option to retry is not available

Answer 1

Hi Wayne,

Thank you for sharing what happened. And you are most welcome. I completely understand the frustration you went through.

A few tips going forward:

1. Pause Updates – In Settings > Windows Update, you can pause updates for a couple of weeks whenever a new cumulative update first rolls out. This gives Microsoft time to patch issues.
2. Create a Restore Point or System Image – Before big updates, set a restore point or keep a backup image on an external drive. This lets you roll back safely without needing a reinstall.

Check the Known Issues Page – Microsoft posts known issues for each update. Worth checking before installing new patches.

An in-place upgrade repair (using the ISO) usually saves apps and settings, so that’s a safer middle option next time.

You’re back up and running now, and with the steps above, you’ll have more control if something like this happens again.

All the best, and thanks again for closing the loop here.

Answer 2

Thanks I will work my way thru this schedule and advise of result

Answer 3

Thanks for reaching out. I will do my best to help. I’ll walk you through this step by step and make sure we cover the right checks.

First, let me ask a few questions:

Did you already try booting into Safe Mode to see if the system is stable there?

Do you have any third-party antivirus or optimization software installed? These can interfere with cumulative updates.

Have you run the Windows Update Troubleshooter yet?

Do you see this KB5065426 listed in Settings > Windows Update > Update History > Failed Updates?

1. Do you have enough free disk space on your system drive (C:)?

Here’s what you can try right now:

Step 1. Open Command Prompt as Administrator and run these commands one by one:

sfc /scannow

DISM /Online /Cleanup-Image /RestoreHealth

This will repair corrupted system files that may have caused the 0x800f0845 failure.

2. Reset Windows Update Components

If corruption is stuck in the update cache, reset it:

net stop wuauserv

net stop cryptSvc

net stop bits

net stop msiserver

ren C:\Windows\SoftwareDistribution SoftwareDistribution.old

ren C:\Windows\System32\catroot2 catroot2.old

net start wuauserv

net start cryptSvc

net start bits

net start msiserver

Then restart and check for updates again.

3. Manually Install the Update

Go to the Microsoft Update Catalog and download the standalone installer for your system (x64). Run it manually.

4. If these steps do not resolve the problem, I recommend performing an in-place upgrade repair of Windows 11 using the latest ISO. This refreshes Windows, keeps your apps and files, and often clears out failed cumulative update loops.

Here's how.

Go to the official Microsoft page:

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

Under "Download Windows 11 Disk Image (ISO)," select Windows 11 (multi-edition ISO) and click Download.

After downloading, right-click the ISO file and click Mount.

Open the new virtual drive that appears and run setup.exe.

On the installer screen

Choose “Keep personal files and apps” when prompted.

Follow the on-screen steps to complete the installation.

This process can take up to 1 hour and may include multiple restarts. After it completes, Windows will be refreshed while keeping all your data intact.

You can also follow the steps outlined in this article.

Troubleshoot problems updating Windows

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