Microsoft recently released Update KB5015814 on Windows 11, but a few users reported that they were unable to install the same update due to an Error Code 0x8000ffff. Once the same error message appears on the screen, the installation process stops, and the suffering users are worried about it. Anyway, this is an easily fixable problem, so you don’t need to worry.

The same error code may arise for various causes, but we are here to assist you in finding a surefire solution. In this article, we have gathered a few solutions to overcome KB5015814 Update Not Installing Error Code 0x8000ffff issue quickly and effectively. Then let’s have a look. 

Fix 1: Restart the System

The first solution to deal with the Update KB5015814 Not Installing Error Code 0x8000ffff issue is to restart your Windows 11 system. When restarting the system, this process will start the system afresh and clear most minor bugs.

Fix 2: Run Update Troubleshooter

Another solution to resolve the KB5015814 Update Not Installing Error Code 0x8000ffff on Windows 11 is running the Update troubleshooter. To do so, 

  • Firstly, press Windows + I altogether to open the Settings menu on your desktop screen.
  • Then click on the System option and choose the Troubleshooter.
  • Now press the Other troubleshooters and click on the Run button next to the Windows update option. 
  • Once done, the said issue may get solved for you.

Fix 3: Restart Windows Update Services

Sometimes restarting the Windows Update service will help you to resolve the KB5015814 Update Not Installing Error Code 0x8000ffff issue on your Windows 11 system. To do so,

  • Firstly, open the Services window on your system screen, find and double-click on Windows Update service.Services
  • Inside the newly appeared screen, set Startup type as Automatic and Service status as Running. 
  • Once done, click on the Restart link from the top left side of the screen and complete the process.
  • Follow the same above steps to restart the Background Intelligent Transfer service.
  • Finally, restart the system and install the latest updates again.

Fix 4: Reinstall Windows 11 Installation Assistant

At times installing Windows 11 Installation Assistant will allow you to get rid of Update KB5015814 Not Installing Error Code 0x8000ffff issue quickly, and you can install the latest updates. To do so,

  • Firstly, launch your regular web browser and navigate to the Windows 11 Installation Assistant page.Windows 11 Installation Assistant
  • Then click on the Download now button under the Windows 11 Installation Assistant section and install it on your system.
  • Once done, restart the system and install the latest updates again.

Fix 5: Reset Windows Update Components

If you encountered KB5015814 Update Not Installing Error Code 0x8000ffff issue on your Windows 11 system, then you should reset Windows Update components to escape from the same issue. To do so,

  • Firstly, type “cmd” in your search box and open the Command Prompt window (Run as administrator) from the search result.
  • Inside the newly appeared screen, type or paste the following commands and press Enter,

SC config trustedinstaller start=auto

 net stop bits

 net stop wuauserv

 net stop msiserver

 net stop cryptsvc

 net stop appidsvc

 Ren %Systemroot%\SoftwareDistribution SoftwareDistribution.old

 Ren %Systemroot%\System32\catroot2 catroot2.old

 regsvr32.exe /s atl.dll

 regsvr32.exe /s urlmon.dl

 regsvr32.exe /s mshtml.dll

 netsh winsock reset

 netsh winsock reset proxy

 rundll32.exe pnpclean.dll,RunDLL_PnpClean /DRIVERS /MAXCLEAN

 dism /Online /Cleanup-image /ScanHealth

 dism /Online /Cleanup-image /CheckHealth

 dism /Online /Cleanup-image /RestoreHealth

 dism /Online /Cleanup-image /StartComponentCleanup

 Sfc /ScanNow 

net start bits

 net start wuauserv

 net start msiserver

 net start cryptsvc

 net start appidsvc

  • When done, restart the system and install the latest updates again. 

Fix 6: Use Media Creation Tool

In most cases, installing the Windows 11 Media Creation tool will allow you to resolve the KB5015814 Update Not Installing Error Code 0x8000ffff issue effectively. To do so

  • Firstly, launch your regular browser and navigate to the Windows 11 Media Creation official webpage. 
  • Then click on the Download now button under the Media Creation tool section and install it on your system. 
  • Once done, the issue might get resolved for you. 

Fix 7: Run SFC Scan

Sometimes corrupt system files prevent you from installing the latest Windows updates on your system. In this case, you need to run an SFC scan to repair all corrupted system files quickly. To do so, 

  • Firstly, open the Command Prompt window by typing “cmd” in your search box and launching the top result. 
  • Then inside the black text screen, type or paste the following command and click on Enter button, 

Sfc /scannow

  • Once done, again paste or type the below-given commands and click on Enter button to restore early repaired system files,

DISM /Online /Cleanup-Image /CheckHealth

DISM /Online /Cleanup-Image /ScanHealth

DISM /Online /Cleanup-Image /RestoreHealth

  • When all the commands are executed, you can install the latest updates on your PC.

Fix 8: Use Microsoft Update Catalog 

If any of the above solutions do not help you, then you should install the problematic update manually. To do so, 

  • Firstly, launch your browser and navigate to the Microsoft Update Catalog page.Microsoft Update Catalog
  • Then in the search box, type Update number “KB5015814” and press OK
  • Now choose the suitable file from the list and install it on your system, and you are done. 

These are all about the KB5015814 Update Not Installing Error Code 0x8000ffff on Windows 11 and its fixes. If you have any queries or concerns regarding this article, you can leave a comment in the comment box below.