2026-05 Security Update (KB5089549) (26200.8457) not installing due to Error 0x800705b9

HappyHippoEaters 20 Reputation points
2026-05-20T19:23:24.88+00:00

I have been Having Trouble getting Update 2026-05 Security Update (KB5089549) (26200.8457) due to Error 0x800705b9, I have followed the guidance of the below link, but the 1st 2 suggestions didn't work, the 3rd was a dead end due to a outdated link, if I can get guidance on how to proceed with option three, or if there is another solution, I would very much Appreciate it.

https://learn.microsoft.com/en-us/answers/questions/4053033/install-error-0x800705b9-for-windows-11-update-kb5

Windows for home | Windows 11 | Windows update
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Answer accepted by question author
David-M 127.3K Reputation points Independent Advisor
2026-05-20T19:59:01.8333333+00:00

Hi. I'm David, and I'm happy to help you.

The third suggestion is an In-place Upgrade. I'll leave the step-by-step instructions with the updated link below.

(If you have a third-party antivirus installed, temporarily disable it during the entire procedure.)

Download the ISO file to perform the procedure:

  1. Access the link below;

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

  1. Under Download Windows 11 Disk Image (ISO), click Select download and select Windows 11 (multi-edition ISO for x64 devices);
  2. Click Download;
  3. Choose the language and click on Confirm;
  4. Then, click 64-bit Download.
  5. Wait for the download to finish and proceed to the procedure below.

After downloading the ISO, do the following:

  1. Double-click the ISO to run;

(After running the ISO, you may need to double-click the Setup file to start the procedure.)

  1. On the Install Windows 11 screen, uncheck I want to help make the installation of Windows better and select Change how Windows Setup download updates;
  2. On the next screen, select Not right now and click Next;
  3. Accept the terms of use;
  4. On the Ready to install screen, select Choose what to keep and select what you want to keep.

(It is in this step that you must check Keep personal files and apps so that all your data is kept.)

  1. Click on Install and wait for the procedure to finish. Your computer may restart several times.

The update may be installed during the In-place Upgrade. Therefore, it may no longer appear in Windows Update. Still, check Windows Update for any pending updates and install them.

If you get any errors or the problem persists, please let me know.

Feel free to ask any questions you may have.

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