| Feature | Details |
|---|---|
| Error Code | 0x80073701 (ERROR_SXS_ASSEMBLY_MISSING) |
| Operating System | Windows Server 2022 |
| Primary Cause | Corrupted or missing files in the Component Store (WinSxS) |
| Recommended Tools | DISM, SFC, Windows Update Reset Script |
| Complexity | Intermediate |
What is Windows Server 2022 Update 0x80073701?
The error code 0x80073701 translates to “ERROR_SXS_ASSEMBLY_MISSING.” It occurs when Windows Update attempts to access a specific system component or assembly in the WinSxS folder that is either corrupted, deleted, or missing.
On Windows Server 2022, this often halts Cumulative Updates (CU). It prevents the server from applying critical security patches until the underlying file system integrity is restored.
Unlike standard connection errors, this is a file-level issue. Fixing it requires repairing the internal component store rather than simply restarting the update service.
Step-by-Step Solutions
Step 1: Run the DISM Tool
The Deployment Image Servicing and Management (DISM) tool is the most effective way to repair the component store. Open PowerShell or Command Prompt as Administrator and run the following commands sequentially.
dism /online /cleanup-image /scanhealth
dism /online /cleanup-image /checkhealth
dism /online /cleanup-image /restorehealthThe /restorehealth command compares your local files to Windows Update servers and replaces any corrupted ones. This process may take several minutes to complete.
Step 2: Use the System File Checker (SFC)
After running DISM, you should verify the integrity of protected system files using the SFC tool. This ensures that the fixes applied by DISM are correctly integrated into the OS.
sfc /scannowIf the scan finds errors, it will attempt to repair them automatically. If it says “Windows Resource Protection found corrupt files but was unable to fix some of them,” you may need to restart and run the command again in Safe Mode.
Step 3: Analyze the CBS Log
If the error persists, you need to identify which specific assembly is missing. Windows logs these details in the CBS.log file. Use the following command to filter the log for the specific error code.
findstr /c:"0x80073701" %windir%\logs\cbs\cbs.log > %userprofile%\desktop\error_log.txtOpen the “error_log.txt” file on your desktop. Look for the “Assembly Missing” entries to see if a specific language pack or feature is causing the conflict.
Step 4: Clean Up the Component Store
Sometimes, old update files interfere with new installations. Cleaning up the WinSxS folder can resolve metadata conflicts that trigger 0x80073701.
dism /online /cleanup-image /startcomponentcleanupThis command removes superseded versions of components. Once completed, restart your Windows Server 2022 instance and try running the update again via the Settings menu.
Step 5: Reset Windows Update Components
If the file system is healthy but the update still fails, the Windows Update database might be stuck. You can reset the update services by stopping them and clearing the cache.
net stop wuauserv
net stop cryptSvc
net stop bits
net stop msiserver
ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
ren C:\Windows\System32\catroot2 catroot2.old
net start wuauserv
net start cryptSvc
net start bits
net start msiserverAfter renaming these folders, Windows will recreate them from scratch the next time you check for updates, bypassing potential database corruption.