How to fix
KB5034121 fails to install
on Windows

Hello. I tried to install the KB5034121 update for Windows 11 but it failed. Is there a way to fix this?

Users may face serious issues if KB5034121[ref en-1] fails to install in Windows 11, especially if they depend on smart card authentication for remote system access. This update particularly addresses a problem that causes devices to shut down after 60 seconds when using a smart card for remote system authentication. The consequence of such abrupt shutdowns is evident in the disruption of workflow and potential loss of unsaved work.

The update also fixes a visual glitch about the smart card icon's appearance during sign-in. When there are several certificates on the smart card, users can run into a scenario where the icon doesn't show up, which could lead to misunderstanding or ambiguity regarding the authentication status. During the sign-in process, this visual irregularity might hinder the user experience and add to a general feeling of uneasiness.

Apart from addressing these issues, the update resolves a known problem with BitLocker data-only encryption. People who depend on mobile device management (MDM) services, like Microsoft Intune, may find it challenging to get reliable data. The efficacy of BitLocker data-only encryption may be compromised by the difference in data retrieval, putting private data at risk of security issues.

These problems have more ramifications than just being inconvenient; they can affect user confidence, data security, and system stability. Frequent shutdowns, unclear authentication statuses, and compromised data encryption are issues that users may encounter. These issues can seriously impair productivity and expose systems to security risks.

In this guide, you will find 6 steps that should help you fix KB5034121 fails to install in Windows 11. You can also run a maintenance tool like [d1] that can fix most system errors, BSODs,[ref en-2] corrupted files, and registry[ref en-3] issues. Otherwise, follow the step-by-step instructions below.

Solution 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

Solution 2. Run Windows Update Troubleshooter

• Click the Windows button and select Settings
• Select System from the left pane, then scroll down on the right pane, and click on Troubleshoot

• Click on Other troubleshooters
• Locate the Windows Update troubleshooter and hit the Run button

Solution 3. Restart Windows Services

• Type services in the search bar and launch the Services utility
• Find Windows Update in the list
• Double-click on it, set the Startup type to Automatic, and click Apply
• Now click on Restart the Service

• Do the same with Background Intelligent Transfer Service

Solution 4. Use the Microsoft Update Catalog

• Go to the official Microsoft Update Catalog website
• Type the KB number KB5034121 into the search bar, and press Enter or click Search

• You will find many different versions on the update – you need to find the one that matches your PC specs and Windows version (as a home user, ignore Windows server versions)
• After picking the correct version, click the Download button and proceed with the on-screen instructions
• Restart your system once done

Solution 5. Reset Windows Update Components

• Type cmd in the search bar.
• Right-click on Command Prompt in the search results.
• Select Run as administrator.
• In the Command Prompt window:
• Type the following commands one by one and press Enter after each:

net stop wuauserv

net stop cryptSvc

net stop bits

net stop msiserver

• Execute the following commands one by one:

net start wuauserv

net start cryptSvc

net start bits

net start msiserver

• Restart your PC.
• Check to see if the issue has been resolved.

Solution 6. Use Installation Media

If none of the previous steps helped you resolve the issue, your current installation of Windows may be corrupt. Perform a repair installation and see if it fixes the issue of updates not installing.

• Visit the official Microsoft website to download Windows 11 Installation Media
• Run the Media Creation Tool and select Create Installation Media for another PC
• Select your USB drive
• Let the Process complete of writing the Installation files to the USB drive
• Click Finish
• On the PC you wish to upgrade, Press Windows + E to open the File Explorer

• Open the Removable drive and click Setup.exe
• Accept the license terms on the next screen
• Confirm the Upgrade options – Files, apps and Settings are kept
• Click Install, and the upgrade should start