How to Fix Windows Update 800b0109 Error? 6 Best Ways

Microsoft frequently fixes minor or major bugs and security patches with new Windows updates. Every time the latest update arrives, ideally you should update your Windows with the latest one. However, not every time you’d get to install the update flawlessly, and many users encounter various problems while installing updates on their PC.

Today we are going to discuss one such error, Windows Update 800B0109 Error. This error occurs with the following message saying “Error(S) found: Code 800B0109 Windows Update encountered an unknown error.” The source of Error 800b0109 could be a number of things such as Windows Registry, Windows File System, Internet access, Windows Update service, File corruption, Misconfiguration, Adware, Virus, and Malware.

Regardless of whatever causes the error, we’re here to find the fix. Moreover, in this post, we shall tell you six possible solutions to resolve the issue. Do note that there’s no universal fix as such. You will have to try out each of the below-mentioned workarounds and see which one works best in your favor. So with that in mind, let’s get started. 

Fix 1: Stop and Start Windows Update Service

Since Error 800b0109 is an update error, to fix this the first thing we will do is stop and restart the Windows Update Service. Further in this method, we are going to do three things–

  1. Stop Windows Update service.
  2. Clean the Windows Update temporary cache folder.
  3. Restart the Windows Update service again.

Stop Windows Update service.

Step 1: Press the Windows-key+S key together to open the search box then search for service.msc in the search box.

Step 2: Open the Services app.

Step 3: In the new window all the services in Windows will show up.

Step 4: Search for Windows Update. To find the Windows Update service easily click on any of the services and type W until you find it or go to the bottom and search for Windows Update.

Step 4: Right-click the Windows Update and then click Stop, Wait for some time until it gets stopped.

Clean the Windows Update temporary cache folder.

Windows Update service has stopped. Now we have to clean the Windows update cache folder. Here are the steps:

Step 1: Press the Windows-Key+R together.

Step 2: Type %windir%\SoftwareDistribution\DataStore in the newly opened window’s search box.

Step 3: Click on OK.

Step 4: You’ll land in a folder containing all the cache files. Select all files by pressing Ctrl+A and Delete all contents of this folder.

Restart Windows Update Service

After clearing all the cache files. We’ll start the Windows Update Service again. Here is how.

Step 1: Go back to the Windows Update service window. (Follow the steps from 1 to 3 of stop windows update service method)

Step 2: Currently it is stopped, to start it again right-click on it and click on Start

So, this is the first method you should try to fix Windows Update 800 error. However, if this method doesn’t work try a different one, shared below —

Fix 2: Run the System File Checker (SFC) Utility

In this method, we’ll run the System File Checker(SFC). SFC is a built-in tool to check the file system of your system. To run it, follow these steps:

Step 1: Press Windows-Key+S simultaneously to open the search box.

Step 2: Type cmd in the search box.

Step 3: You’ll see Command Prompt App from the list of results. From the right preview pane, click on the Run as administrator and then select Yes.

Step 4:  Type sfc/scannow (note the space between “sfc” and “/”) and press Enter.

Step 6: Wait for some time, this step may take a few minutes to start and up to 30 minutes to complete.) You can minimize the windows and do other stuff.

Step 7: After you see a message that says, “Verification 100% complete,” type Exit.

Step 8: Now Restart your computer and then Check for Updates. The update error should be fixed by now.

Fix 3: Check Disk Utility

You can check the logical and physical errors of the hard disk. Disk Utility can be used to fix Windows Update-related errors.

Step 1: In the search box on the taskbar, type cmd

Step 2: From the right preview windows, Click on Run as administrator, and then select Yes.

Step 3: Run as administrator, and then select Yes.

Step 4: Type chkdsk C: /f (note the space between “C:” and “/”) and press the Enter key.

Step 5: Restart your PC when the process is finished.

Fix 4: Check the Windows Firewall

Error in Firewall settings also can be a source of Error 800b0109 Windows Update Error. In order to fix the update error make sure everything is fine in the Windows Firewall setting. To make sure follow the steps:

Step 1: In the search box on the taskbar, type ‘Check Firewall Status’.

Step 2:  Open it.

Step 3: Take a look if there is an error. If there are no red highlights then everything is fine and you don’t need to take any action.

Fix 5: Clean Up Files

Clearing some temp files and unwanted system files may cure the  Windows 800 Update Error. Here we are going to clear temp, %temp%, and cleanmgr files. Here is how.

Clean Temp Files for System

Step 1: Type Windows-Key+R together. A “Run” dialog box window will pop up.

Step 2: Type the command temp and press Enter key.

Step 3: Now the Temp folder will open up. Select all the files of the folder by pressing Ctrl+A at once.

Step 4: Press the Shift+Delete button to permanently delete all the files.

> Note: Some files may not be able to be deleted. If you are prompted about files that are missing or in use, click the check box next to “Do this for all current items” and click “Skip.”

Clean %temp% files

Step 1: Press the Windows Button + R to open the “Run” dialog box.

Step 2: Enter this text: %temp%

Step 3: Click “OK.” This will open your temp folder.

Step 4: Now, repeat the same steps as mentioned before in Step 3 to Step 5.

Clean up unwanted System files

Step 1: Press the Windows Button + R to open the “Run” dialog box.

Step 2: Enter this text: cleanmgr.exe

Step 3: Now disk cleanup windows shall open. Select the drive you want to clean up. (Normally C: Drive) Click OK.

Step 4: Select the files you want to delete from your system. You can check the list of files. Select all except Recycle Bin and Previous Windows Installations.

Step 5: Click the OK button to start cleaning up. Wait until it is done.

Fix 6: Reset your PC

If none of the above-shared methods are able to fix the 800b0109 Error, only then you should try to Reset This PC option. It will reinstall the Windows of your PC, however, you get to choose whether you want to keep or remove your personal files. To reset your PC, follow these steps:

Before you proceed further let me warn you again – you only choose this method if none of the other methods work. Resetting your PC is not the ideal solution to a minor error like this. Reset This PC is a repair tool for serious operating system problems. Reset This PC removes all of your software or driver, meaning you will have to reinstall that software and driver.  

Step 1: Press Windows Key + S to open the Search bar and type Reset this PC.

Step 2: Open it.

Step 3: Click the Get Started button.

Step 4: Click on the option that says Keep my files.

Now sit back and wait until your PC reset successfully.

Bottom Line

So these were the best fixes for the error 800b0109. Hope you found the article helpful. Please comment on which method worked for you. Also, if the problem still persists, feel free to let us know.

Pintu is the admin and editor-in-chief at Gizmoradar. He crafts actionable tech guides related to Windows, Android, Mac, and iOS. He's been writing how-to guides for about 5+ years now and has covered many topics.

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