Quick Summary
Error code 0x80073701, often described as ERROR_SXS_ASSEMBLY_MISSING, indicates that a required Windows component or assembly is missing or corrupted. This typically prevents updates or feature installations from completing successfully.
Common Causes
- Corrupted Component Store: The Windows component store, which contains the files needed for installing updates and features, may be damaged due to disk errors, incomplete updates, or malware infections.
- Missing System Files: Critical system files required for specific updates or features might be accidentally deleted or corrupted, leading to the error.
- Conflicting Software: In rare cases, third-party software or poorly designed drivers may interfere with the update process and cause component store inconsistencies.
Step-by-Step Fixes
Method 1: Run System File Checker (SFC)
Step 1: Open Command Prompt as an administrator. Type 'cmd' in the Windows search bar, right-click 'Command Prompt', and select 'Run as administrator'.
Step 2: In the Command Prompt window, type 'sfc /scannow' and press Enter.
Step 3: Wait for the scan to complete. This process may take some time. If any errors are found, SFC will attempt to repair them automatically.
Step 4: Once the scan is finished, restart your computer.
Method 2: Use DISM to Restore Health
Step 1: Open Command Prompt as an administrator (as described in the previous method).
Step 2: Type the following command and press Enter: 'DISM /Online /Cleanup-Image /RestoreHealth'
Step 3: Wait for the command to complete. This process may take a considerable amount of time, especially if the component store is heavily corrupted.
Step 4: If DISM cannot download the necessary files from Windows Update, you can specify a Windows installation source. Mount a Windows ISO image or insert a Windows installation USB drive, and then run the following command, replacing 'D:\sources\install.wim' with the actual path to the 'install.wim' file on your installation media, and '/Index:1' with the index of the Windows edition you are repairing: 'DISM /Online /Cleanup-Image /RestoreHealth /Source:wim:D:\sources\install.wim:1 /limitaccess'
Step 5: Restart your computer after DISM finishes.
Method 3: Run the Windows Update Troubleshooter
Step 1: Open the Settings app (Windows key + I).
Step 2: Go to 'Update & Security' > 'Troubleshoot'.
Step 3: Select 'Windows Update' and click 'Run the troubleshooter'.
Step 4: Follow the on-screen instructions to complete the troubleshooting process.
Step 5: Restart your computer after the troubleshooter is finished.
Method 4: Manually Reset Windows Update Components
Step 1: Open Command Prompt as an administrator (as described above).
Step 2: Stop the Background Intelligent Transfer Service (BITS), the Windows Update service, the Cryptographic service, and the MSI Installer service by running the following commands one by one, pressing Enter after each:
net stop wuauserv
net stop cryptSvc
net stop bits
net stop msiserver
Step 3: Rename the SoftwareDistribution and Catroot2 folders by running these commands:
ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
ren C:\Windows\System32\catroot2 Catroot2.old
Step 4: Start the services you stopped in Step 2 by running these commands:
net start wuauserv
net start cryptSvc
net start bits
net start msiserver
Step 5: Restart your computer.