Windows is one of the most popular and stable OS on the planet. Microsoft puts a lot of work into its flagship product and the result is an operating system that gets frequent updates that make it even better. However, these updates might not always have the intended effect as sometimes they can break more functionality than they aim to fix.
In this article, we’re talking about what issues the KB5021234 update can cause in Windows and what you can do to fix them.
What issues does KB5021234 cause?
A majority of user reports lean towards installation errors with the KB5021234 update. This can be caused because of a number of reasons including but not limited to the following:
- Outdated Windows version.
- Corrupt system files.
- Windows update components aren’t working properly.
Also read: Windows update error 80072ee2: 5 Fixes
How to fix these issues?
You can try out the following seven fixes.
Restart your PC
Restarting your PC is by far one of the most simple and effective solutions to just about any problem you run into while using Windows. Graphics issues, network problems, update glitches, rebooting got you covered.
It’s also not a bad idea to check your internet connection real quick. At times a dead or inactive internet connection can be the root cause of a lot of problems.
Disable any third-party antivirus
Microsoft has revealed that certain Symantec and Norton antivirus versions do not work well with this particular update. Try disabling or uninstalling any third-party security software that you might have on your PC to see if you can install the update then.
Run an SFC scan
Corrupt files are the number one reason why your PC might be behaving weirdly. Here’s how you can get rid of them and potentially resolve your issue.
Step 1: Press Windows Key + S to bring up the Cortana/Search box and search for Powershell. Open Windows Powershell from the search results.

Step 2: Type sfc /scannow to scan your system for issues.

Step 3: If the SFC scan finds any problem, use the following command to resolve them.
DISM /Online /Cleanup-Image /RestoreHealth

Restart your PC, and the error should be gone.
Also read: How to fix issues with KB5019959 Windows update?
Run the Windows 11 update troubleshooter
Just like Windows 10, Windows 11 also comes with a bunch of helpful troubleshooters that’ll automatically detect and resolve any problems your PC might be facing. The same goes for the update troubleshooter, here’s how.
Step 1: Press the Windows key and search for Troubleshoot settings. Click the corresponding search result.

Step 2: Click Other troubleshooters.

Step 3: Scroll to find the Update Troubleshooter and click the Run button.

This should automatically fix the problem.
Restart the Windows Update Service
The Windows Update service is responsible for periodically checking for any new updates Microsoft may release. Restarting this service can help get your machine on track.
Step 1: Press Windows Key + R to open the Run prompt. Type services.msc and hit enter.

Step 2: Find the Windows Update service. Right-click it and select Stop.

Step 3: Return to the Services Console and restart the Windows Update service in step 2.

Also read: How to cancel Canva subscription?
Reset Windows Update modules
Another thing you can try is completely resetting Windows Update modules to get them to work properly.
Step 1: Press Windows Key + X to open the Quick Access menu and click on Command Prompt (Admin).

Step 2: Type the following command in the prompt and press Enter.
net stop wuauserv cd %systemroot% ren SoftwareDistribution SoftwareDistribution.old net start wuauserv net stop bits net start bits net stop cryptsvc cd %systemroot%\system32 ren catroot2 catroot2.old net start cryptsvc regsvr32 Softpub.dll /s regsvr32 Wintrust.dll /s regsvr32 Initpki.dll /s regsvr32 Mssip32.dll /s

Install the latest version manually
If nothing else works, instead of relying on Windows updates, you can head over to Microsoft’s official download page and download the latest version of Windows manually and install it on your system.
Alternatively, you can also use the Media Creation Tool from Microsoft to install Windows 10 on a bootable flash drive and reinstall the OS on your machine.
The Windows Media Creation tool is a great way to install Windows and repair the OS. Using this, you can perform a clean installation or repair your OS without affecting your personal data.
You can download the Media Creation Tool here
Also read: Windows update error 0x80240fff: 8 Fixes