The Problem:

Windows failed to install the cumulative update KB5051979 for Microsoft server operating system version 21H2, resulting in error code 0x8024200B. This issue prevents the system from receiving important updates, potentially leaving it vulnerable to security risks and missing out on performance improvements.

Problem Analysis:

The error 0x8024200B is typically associated with issues in the Windows Update process, often indicating that the update was downloaded but could not be installed. Users may notice this error in the Windows Update history or when manually attempting to install the update. The problem often begins after a scheduled update attempt or a manual update check, where the system reports failure in applying the update.

Root Cause:

The root cause of the error 0x8024200B can be traced to several potential issues:

• Corrupted update files or incomplete downloads.


• Conflicts with existing system files or installed software.


• Insufficient disk space or system resources.


• Problems with Windows Update services or components.

Solution:

To resolve the error 0x8024200B, follow these steps:

1. Run the Windows Update Troubleshooter:

• Open Settings > Update & Security > Troubleshoot.


• Select Windows Update and click Run the troubleshooter.


• Follow the on-screen instructions to identify and fix any issues.

2. Clear Windows Update Cache:

• Open Command Prompt as an administrator.


• Stop the Windows Update service:
  

   net stop wuauserv



• Stop the Background Intelligent Transfer Service (BITS):
  

   net stop bits



• Navigate to the SoftwareDistribution folder and delete its contents:
  

   del /f /s /q %systemroot%\SoftwareDistribution\*



• Restart the services:
  

   net start wuauserv
  
   net start bits

3. Check Disk Space:

• Ensure there is sufficient free space on the system drive. At least 20% of the drive should be free for optimal performance.

4. Perform a System File Check:

• Run Command Prompt as an administrator.


• Execute the System File Checker tool:
  

   sfc /scannow



• Allow the process to complete and fix any detected issues.

5. Manually Download and Install the Update:

• Visit the Microsoft Update Catalog.


• Search for the update KB5051979.


• Download the appropriate version for your system architecture (x64).


• Run the downloaded file to manually install the update.

6. Check for Conflicting Software:

• Review recently installed software or updates that might conflict with the update.


• Uninstall any suspicious software and attempt the update again.

7. Review Windows Update Logs:

• Check the Windows Update log files for more detailed error messages.


• Use the Event Viewer to look for related errors in the system logs.

If these steps do not resolve the issue, consider reaching out to Microsoft Support for further assistance.