How to fix
KB5036979 fails to install
on Windows

Fix 1. Run Windows update troubleshooter

The Windows Update Troubleshooter is designed to automatically diagnose and resolve issues related to Windows updates. It checks for common problems that might prevent updates from installing and attempts to fix them.

• Type Troubleshoot in Windows search and press Enter.
• Select Additional troubleshooters.
• Find Windows Update from the list.
• Select it and click Run the troubleshooter.
• Restart your computer when the update process finishes.

Fix 2. Check the time and date

Incorrect system time and date settings can interfere with Windows Update because they can cause security certificate mismatches and other issues that prevent the update servers from verifying the authenticity of your system.

• Type in Control Panel in Windows search and press Enter.
• Go to Clock and Region and click on Date and Time.
• Pick the Internet Time tab and select Change Settings.
• Make sure that the Synchronize with an Internet time server box is ticked.
• Click Update now and OK.

Fix 3. Temporarily disable third-party security software

Third-party security software can sometimes interfere with the installation of Windows updates. These programs often incorporate firewall features or system monitoring that can mistakenly block or restrict Windows Update servers or processes. Disabling such software temporarily can help determine if it is the cause of the update issue.

Before disabling any security software, ensure your system is not at risk of immediate threats. After disabling, attempt to run the update again. Once the update is complete or if the problem persists, re-enable your security software to protect your system.

Fix 4. Perform Disk Cleanup

Disk Cleanup helps free up space on your hard drive and can remove temporary files that may be interfering with the update process.

• Type Disk Cleanup in Windows search and press Enter.
• Select your main drive (C: by default).
• Select appropriate fields (Temporary files, Recycle Bin, etc.) and click OK.
• If you want a more thorough cleanup and require even more space, select Clean system files in the Disk Cleanup window.
• Select your main drive again - Windows will compute how much space can be retrieved.
• The largest data dumps are usually accumulated in Windows Update and Delivery Optimization sections, although Temp files can also take a lot if it hasn't been cleaned.
• Select appropriate fields and click OK - Windows will remove all these files from your device and free up space.

Fix 5. Check update-related services

Windows Update relies on several services to function properly. Ensuring these services are running can resolve issues with updates not installing.

• Type in Services in Windows search and hit Enter.
• Scroll down a bit to find Background Intelligent Transfer Service (BITS).
• If it is already running, right-click and select Restart.
• If the service is not running, double-click it, and pick Automatic under the Startup type drop-down menu.
• Click Start, Apply, and OK.
• Repeat the process with the Windows Update, Cryptographic, and Windows Installer services.

Fix 6. Reset Windows update components

Resetting Windows Update components clears the update history, cache, and restarts all related services, which can resolve persistent update problems.

• Type cmd in Windows search.
• Right-click on Command Prompt and pick Run as administrator.
• The User Account Control window will ask whether you want to allow changes - click Yes.
• In the new window, use the following commands, pressing Enter after each:
  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 
• Restart your system.

Fix 7. Run SFC and DISM scans

Running these commands in an elevated Command Prompt can help you fix corrupted system files and Windows image files, respectively, which can impede update installations.

• Open Command Prompt as administrator.
• In the Command Prompt window, paste the following command and hit Enter:
  sfc /scannow
• Once the scan is complete, use the following commands and press Enter after each:
  Dism /Online /Cleanup-Image /CheckHealth
  Dism /Online /Cleanup-Image /ScanHealth
  Dism /Online /Cleanup-Image /RestoreHealth
  
• (Note: if you get an error executing this last command, add /Source:C:\RepairSource\Windows /LimitAccess to it and try again).
• Restart your computer.