Windows Update Error 0x80073701

What is WU-0x80073701?

The referenced assembly could not be found. This error indicates missing or corrupted assembly manifest files inside the Windows Component Store (WinSxS).

Common Causes

• Missing assembly metadata required for verifying cumulative update configurations.
• Corrupted Component-Based Servicing (CBS) log references in the system registry.
• Interrupted installation steps from previously attempted updates.

Step-by-Step Fix Guide

• 1
  Run the DISM StartComponentCleanup command to purge outdated and corrupted update logs.
• 2
  Use the System File Checker (sFC) tool to scan and restore missing assemblies.
• 3
  Check the CBS.log file to identify and manually reinstall the missing package identifiers.

Commands & Diagnostics