Software⏱️ 3 min read📅 2026-05-29

How to Fix: Windows MSU Patch Installation Fails at 94% Post-Restart with "Undoing

Windows MSU Patch Installation Fails at 94% Post-Restart with Undoing Changes

Quick Answer: Try running the Windows Update Troubleshooter or using the built-in DISM tool to scan and repair system files, then attempt the update again.

The error occurs when the Windows MSU patch installation fails to complete due to a corrupted state of the Windows Update Service (WUS) or the Component-Based Servicing (CBS) component. This can happen when there are issues with the Windows Update Catalog, the Windows Installer, or other related components.

⚠️ Common Causes

  • Corrupted Windows Update Catalog
  • Windows Installer issues
  • Component-Based Servicing (CBS) component problems

🛠️ Step-by-Step Verified Fixes

Method 1: Reboot and Retry

  1. Step 1: Restart your computer and wait for it to fully boot up.
  2. Step 2: Attempt to install the MSU patch again using WUSA.

Method 2: Run DISM

  1. Step 1: Open Command Prompt as an administrator and run the following command: `dism /online /cleanup-image /restorehealth`.
  2. Step 2: Restart your computer and attempt to install the MSU patch again using WUSA.

Method 3: System File Checker (SFC) Scan

  1. Step 1: Open Command Prompt as an administrator and run the following command: `sfc /scannow`.
  2. Step 2: Restart your computer and attempt to install the MSU patch again using WUSA.

💡 Conclusion

By following these steps, you should be able to resolve the issue and successfully install the Windows MSU patch. If you continue to experience problems, it may be necessary to seek further assistance from a qualified IT professional.

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