How to fix
Windows update error 0x800b0109
on Windows

Hello. I keep trying to install new Windows updates but I receive the 0x800b0109 error. How do I fix it?

The Windows update error code 0x800b0109 occurs when the Windows operating system is unable to update due to a certificate verification error. This error can be caused by a variety of factors, including incorrect date and time settings, problems with Windows Update components, and issues with your system's security certificates.

Updating Windows ensures that your computer is running with the most recent security patches and software updates, which can help protect your system from viruses, malware, and other online threats. Furthermore, updates can improve your computer's performance and fix bugs that may cause system crashes or other problems.

Windows updates can include a variety of updates, including security updates, feature updates, and driver updates. Security updates are intended to patch operating system vulnerabilities and protect against potential security threats. Feature updates, on the other hand, add new features and functionality to the operating system, whereas driver updates improve hardware device compatibility and performance.

If the error 0x800b0109 is not resolved, it can prevent your system from receiving critical security updates, potentially leaving your computer vulnerable to security threats. It may also cause performance issues and make installing new software or hardware devices difficult.

In this guide, you will find 8 steps that should help you fix Windows update error 0x800b0109. You may also try a maintenance tool like [d1] that can fix most system errors, BSODs,[ref en-1] corrupted files, registry[ref en-2] issues, or clear cookies and cache.[ref en-3] Otherwise, follow the step-by-step instructions below.

Method 1. Repair Corrupted System Files

Use Command Prompt commands to repair system file corruption:

• Open Command Prompt as administrator
• Use the following command and press Enter:
  sfc /scannow

• Reboot your system
• If SFC returned an error, then use the following command lines, pressing Enter after each:
  DISM /Online /Cleanup-Image /CheckHealth
  DISM /Online /Cleanup-Image /ScanHealth
  DISM /Online /Cleanup-Image /RestoreHealth

Method 2. Run the Update Troubleshooter

• Press the Windows key + X and go to Settings.
• Go to Update and Security.
• Click Troubleshooter.

• Select Additional troubleshooters.
• Run the Update troubleshooter.
• Restart the computer.

Method 3. Check Disk

Ensure that your disk is not damaged. You can perform checks using Administrative Command Prompt:

• If you are using an HDD as your main driver (where your operating system is installed – C: by default), use the following command and press Enter:
  chkdsk c: /f
• If you are using SSD, use this command:
  chkdsk c: /f /r /x

• If you receive an error, type in Y and hit Enter.
• Restart your device to perform the check.

Method 4. Restart Windows Services

• Press Windows + R to open the Run box.
• Type in services.msc and press OK.
• Double-click Background Intelligent Transfer Service.

• If the Startup status lists Stopped, click Start and then click OK.
• If the status is Running, right-click then select Restart.
• Locate the Windows Update service and double-click it.
• If the Startup status lists Stopped, click Start and OK. If the status is Running, right-click, then select Restart.

Method 5. Update Drivers

Outdated drivers could be the cause of this issue. In this case, you can fix it automatically by using [rev id="DriverFix"], which will scan your PC for missing and out-of-date device drivers. Or you can update them manually:

• Open Settings
• Click on Update & Security
• Click on Windows Update
• Click the Check for updates button
• Click the View optional updates option
• Click the Driver updates tab
• Select the driver you want to update
• Click the Download and install button

If the View optional updates link is not available after checking for updates, then Windows Update does not have any new drivers or any updates for other products at that particular time.

Method 6. Use the Microsoft Update Catalog

Whenever Windows updates fail to install automatically, you can always try doing it manually. First, you need to find out which KB number is relevant to you.

• Right-click Start button and pick Settings.
• Go to Update & Security.
• On the right, locate and click View update history.
• From the list, note the KB number that fails to install with the error code.

• Go to Microsoft Update Catalog page, type in the KB number, and press Search.
• Download the update and install it manually.

Method 7. Reset Windows Update Components

• Open Command Prompt as administrator again.
• Copy and paste 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 PC.

Method 8. Upgrade Install Windows

• Download Windows 10 installation media or Windows 11 installation media from the official website.
• Open the tool once it is installed.

• Agree to license terms.
• Choose Upgrade this PC now.
• Wait for the update to be installed.