Lately, several Windows 11 users complained that they are unable to install the Update KB5009566 on their system even after numerous attempts, and they are very concerned about the same. The users who suffered from the same issue received a restart error prompt while in the installation process, and after the system restarts, nothing happened as planned.

There might be several reasons for the same issue, but it is an easily solvable one. To get rid of the Windows Update KB5009566 Not Installing issue, you can walk through this article till the end to obtain all the possible solutions. So, without further ado, let’s jump into the detailed solutions. Let’s have a look.

Fix 1: Run Windows Update Troubleshooter:

As a first attempt to resolve the Windows Update KB5009566 not installing issue on Windows 10/11, you need to run the built-in troubleshooter tool. This tool will erase most of the temporary errors as quickly as possible. To do so,

  • Firstly, press Windows + I altogether to open the Settings app on your desktop.
  • Then select System from the left side of the window and click on Troubleshoot option.
  • On the newly opened window, click on the Other troubleshooters option.
  • In the new screen, click on the Run button beside the Windows Update option.
  • Finally, try again to install the update and see the changes.

Fix 2: Install Windows 11 Installation Assistant:

Another solution to get rid of the Windows Update KB5009566 Not Installing issue is installing Windows 11 Installation Assistant on your system. To do so,

  • Firstly, go to the Windows Installation Assistant page.Windows 11 Installation assistant
  • Then click on the Download button under the Window 11 Installation Assistant.
  • And open the download folder, right-click on the Windows11InstallationAssistant folder, and select its Properties.
  • Inside the Properties window, select the Compatibility tab and tick the check box beside Run this program in compatibility mode for.
  • Then tap on the down arrow under this option and select Windows 7 from the list.
  • Now click on Apply and OK button. Then again, open the Windows11InstallationAssistant folder and install it on your system, and you are done.

Fix 3: Install Windows Update KB5009566 Manually:

If the Windows Update KB5009566 is not installed in the normal procedure, then you need to install it manually. To do so,

  • Firstly, open your browser and go to the Microsoft Update Catalog webpage.
  • Then in the search box, type the Update KB number and press Enter. (Here, it is “KB5009566“).
  • Now select the file compatible with your system, then download and follow the onscreen instructions to install it on your system.
  • You are done and see the improvement.

Fix 4: Reset Windows Update Components:

Sometimes resetting the Windows Update components might help you to resolve the Windows Update KB5009566 Not Installing issue on your Windows 11. To do so,

  • Firstly, type cmd in your search box, select the Command Prompt windows from the search result and open it with administrative access.
  • Inside the Command Prompt, type the following commands one after another and press Enter,

net stop bits

 net stop wuauserv

 net stop appidsvc

 net stop cryptsvc

 Del “%ALLUSERSPROFILE%\\Application Data\\Microsoft\\Network\\Downloader\\*.*”

 rmdir %systemroot%\\SoftwareDistribution /S /Q

 rmdir %systemroot%\\system32\\catroot2 /S /Q

 regsvr32.exe /s atl.dll

 regsvr32.exe /s urlmon.dll

 regsvr32.exe /s mshtml.dll

 netsh winsock reset

 netsh winsock reset proxy

 net start bits

 net start wuauserv

 net start appidsvc

 net start cryptsvc

  • Once you executed all these commands, exit from the window and restart the system.
  • Finally, check the update installation issue resolved for you.

Fix 5: Run SFC Scan:

If any system files get damaged, then also you can’t install the Update KB5009566 on your Windows 10/11. The possible solution here is running the SFC scan to repair those missing files. To do so,

  • Firstly, type cmd in your search box, open the Command Prompt window from the search result and open it with administrative access.
  • Inside the Command Prompt, type the following command and press Enter key,

Sfc /scannow

  • After executing the command, restart the system and install the update again.

Fix 6: Install Media Creation tool:

At times, simply installing the Windows Media creation tool might help you to resolve the same issue. to do so,

  • Firstly, go to the Microsoft Media Creation tool download webpage.
  • Click on the Download button below the Media creation tool and follow the onscreen install the file on your system.
  • Then, select the ISO file in the setup window and save the file.
  • Finally, open the downloaded folder, click on the setup file and complete the installation and update process.

Fix 7: Restart Windows Update Service:

If any of the above solutions do not help you, then you need to restart the Windows Update service. To do so,

  • Firstly, press Windows + R altogether to open the RUN dialog box, then type services.msc and click OK.
  • Inside the Services window, scroll down and right-click on the Windows Update and select its Properties.
  • Then set Startup type as Automatic and Service status as Start, then save the changes.
  • Finally, try again to install the missing update and see the changes.

So, these are all about the fixes for the Update KB5009566 Not Install on Windows 10/11 issue. However, if you have any queries or doubts after reading this article, then please leave a comment in the below-given comment box.