Windows Cumulative Update Failure 0x80073701 – Complete Fix Guide (2026)

Why Windows Cumulative Update Failure 0x80073701 Happens
1. Restart Windows Update Services
2. Run Windows Update Troubleshooter
3. Clear the SoftwareDistribution Folder
4. Run DISM and SFC Scans
5. Check System Health with DISM and SFC (Enhanced)
6. Reset Windows Update Components Manually
7. Free Up Disk Space
8. Disable Third-Party Antivirus Temporarily
9. Advanced Troubleshooting
Conclusion
FAQ

Quick Answer
Windows Cumulative Update Failure 0x80073701 indicates that a Windows update installation failed due to system file corruption or component store issues. The error code translates to ERROR_SXS_ASSEMBLY_MISSING, meaning a required assembly is missing or corrupted. The most effective fixes include running DISM and SFC scans, clearing the SoftwareDistribution folder, resetting Windows Update components, and performing a System Restore. For persistent cases, an in-place upgrade can repair the system without losing your files. For more update troubleshooting, visit our Windows 11 Troubleshooting Hub.

Why Windows Cumulative Update Failure 0x80073701 Happens

Windows Cumulative Update Failure 0x80073701 occurs when the Windows Update service cannot install a cumulative update because the system’s component store (WinSxS) is corrupted or missing necessary files. The error code 0x80073701 corresponds to ERROR_SXS_ASSEMBLY_MISSING, which indicates that a required side-by-side assembly file is not present. This can happen after an incomplete update installation, a sudden power loss, or due to malware infection. It is also common after upgrading to a new Windows version without proper cleanup. For official Microsoft documentation, refer to the Windows Update Error Reference.

The error is closely related to other update failures like Windows 11 Update Error 0x800f081f and Windows 11 Update Error 0x80070002, which also point to component store corruption. Unlike those, 0x80073701 specifically indicates a missing assembly, so repairing the component store is the primary solution.

Before diving into fixes, ensure you have a stable internet connection and at least 10 GB of free space on your system drive. If you have recently installed a major update or feature update, consider rolling back to a previous state first. For a comprehensive guide on update errors, see our Windows 11 Troubleshooting Hub.

⚠️ Warning: Do not attempt to manually replace missing assemblies from the WinSxS folder. Use the official DISM tool to repair the component store instead.

1. Restart Windows Update Services

Before diving into deeper repairs, restarting the Windows Update and related services often clears temporary glitches that can cause Windows Cumulative Update Failure 0x80073701.

Press Win + R, type services.msc, and press Enter.
Locate Windows Update, Background Intelligent Transfer Service (BITS), and Cryptographic Services.
Right-click each and select Restart.
If any service is stopped, right-click and select Start.
Close the Services window and attempt to check for updates again.

✅ Expected Result: This may resolve the error immediately. If not, proceed to the next method.

2. Run Windows Update Troubleshooter

Windows includes a built-in troubleshooter that can automatically detect and fix common update-related problems, including Windows Cumulative Update Failure 0x80073701.

Open Settings > System > Troubleshoot > Other troubleshooters.
Click Run next to Windows Update.
Allow the tool to scan for issues and apply fixes.
Restart your PC after the troubleshooter completes.

💡 Quick Tip: If the troubleshooter is not available, you can run it from Command Prompt: msdt.exe -id WindowsUpdateDiagnostic.

3. Clear the SoftwareDistribution Folder

The SoftwareDistribution folder holds temporary update files. Corrupted files here can interfere with the update process and cause Windows Cumulative Update Failure 0x80073701.

Open Command Prompt as Administrator.

Stop update-related services:

net stop wuauserv
net stop bits
net stop cryptSvc
net stop msiserver

Delete the contents of the SoftwareDistribution folder:
```
del /f /s /q C:\Windows\SoftwareDistribution\*.*
```
Also clear the Catroot2 folder (optional but helpful):
```
del /f /s /q C:\Windows\System32\catroot2\*.*
```

Restart the services:

net start wuauserv
net start bits
net start cryptSvc
net start msiserver

Restart your PC and retry updates.

⚠️ Warning: Deleting the SoftwareDistribution folder will erase your update history, but installed updates remain unaffected.

4. Run DISM and SFC Scans

The core fix for Windows Cumulative Update Failure 0x80073701 is repairing the system component store. DISM (Deployment Imaging Service and Management Tool) is designed specifically for this purpose. SFC (System File Checker) repairs system files.

Open Command Prompt as Administrator.
Run DISM to check the component store health:
```
DISM /Online /Cleanup-Image /CheckHealth
```
If corruption is detected, run the restore command:
```
DISM /Online /Cleanup-Image /RestoreHealth
```
This may take 15-20 minutes and requires an internet connection.
After DISM completes, run SFC:
```
sfc /scannow
```
Restart your PC and check for updates again.

✅ Expected Result: DISM will repair the component store, and SFC will fix system files. This is the most effective method for resolving this error. For more on DISM, see our How to Use DISM Windows 11 guide.

5. Check System Health with DISM and SFC (Enhanced)

If the initial DISM and SFC scans did not resolve the error, perform a more thorough health check using additional parameters.

Run DISM with the /Source parameter to use an external source (like a Windows ISO) if online repair fails:
```
DISM /Online /Cleanup-Image /RestoreHealth /Source:esd:\\path\to\install.esd /LimitAccess
```
Alternatively, use dism /online /cleanup-image /restorehealth /source:wim:\\path\to\install.wim:1 /limitaccess.
After that, run sfc /scannow again.
If SFC reports that it cannot repair some files, check the CBS log at C:\Windows\Logs\CBS\CBS.log for details.

🔁 Alternative Solution: If you do not have installation media, you can mount an ISO or use the Windows Update source with /Source:http://.../ — but online repair is usually sufficient.

6. Reset Windows Update Components Manually

If the error persists, a full reset of Windows Update components is often effective. This process stops services, renames folders, and re-registers DLL files.

Open Command Prompt as Administrator.

Run the following script (copy and paste each line):

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 msiserver

After this, register Windows Update DLLs:

regsvr32 wups2.dll /s
regsvr32 wuapi.dll /s
regsvr32 wuaueng.dll /s
regsvr32 wucltui.dll /s
regsvr32 wups.dll /s
regsvr32 wuwebv.dll /s

Restart your PC and attempt to install the cumulative update again.

⚠️ Warning: Renaming these folders is safe but will clear your update history. The folders will be recreated automatically.

7. Free Up Disk Space

Insufficient disk space can cause cumulative update failures. Ensure you have at least 10 GB free on the system drive.

Open Settings > System > Storage.
Enable Storage Sense to automatically free up space.
Run Disk Cleanup: type cleanmgr in Start, select the system drive, and clean temporary files and Windows Update cleanup.
Uninstall unused apps and delete large files.
Restart and try updating again.

💡 Quick Tip: Use cleanmgr /sageset:1 to customize Disk Cleanup options, then cleanmgr /sagerun:1 to run it.

8. Disable Third-Party Antivirus Temporarily

Some antivirus software can interfere with Windows Update by blocking system file modifications. Temporarily disabling such software may resolve Windows Cumulative Update Failure 0x80073701.

Open your antivirus application.
Look for an option to disable real-time protection or pause protection.
Alternatively, add Windows Update to the exclusion list.
Attempt the update again.
Remember to re-enable protection after the update completes.

❌ Common Mistake: Forgetting to re-enable antivirus after the update. Always turn it back on to maintain security.

9. Advanced Troubleshooting

If the error still persists, try these advanced solutions.

Perform a System Restore

If the error started after a recent system change, use System Restore to roll back. Boot into Recovery Environment (shift+restart) and select Troubleshoot > Advanced Options > System Restore. For a detailed guide, see our How to Use System Restore Windows 11 article.

Use the Windows Update Medic Service

Windows 11 includes a Windows Update Medic Service that can repair the update service itself. Enable it by running in Command Prompt as Admin:

sc config wuauserv start=auto
sc config wuauserv depend= "RpcSs/Winmgmt"
sc start wuauserv

In-Place Upgrade (Repair Install)

An in-place upgrade reinstalls Windows while preserving your personal files and apps. Download the latest Windows 11 ISO from Microsoft, mount it, and run setup.exe. Choose “Keep personal files and apps”. This replaces corrupted system files and usually resolves Windows Cumulative Update Failure 0x80073701. This is also effective for other stubborn errors like Windows 11 Update Stuck.

Check for Malware

Run a full system scan using Windows Defender Offline or a trusted third-party tool. Malware can corrupt system files and block updates. See our How to Scan Malware Windows 11 guide.

If you have exhausted all options, consider using the Windows Update Troubleshooter from the Microsoft support site, or contact Microsoft Support. For more BSOD and update guides, check our Windows 11 Troubleshooting Hub.

Conclusion

Windows Cumulative Update Failure 0x80073701 is a component store corruption error that can be fixed with systematic troubleshooting. The most reliable solutions are running DISM and SFC scans, clearing the SoftwareDistribution folder, and resetting Windows Update components. If these fail, an in-place upgrade is a safe, non-destructive final step. Always ensure you have backups before proceeding with advanced repairs.

Regular maintenance, such as running DISM monthly and keeping your system updated, can prevent this error from recurring. For more update-related fixes, explore our Windows 11 Troubleshooting Hub, where you’ll find guides on 0x800f081f, 0x80070002, and Update Stuck Fix.

Related Guides

FAQ

What does Windows Cumulative Update Failure 0x80073701 mean?

Error 0x80073701 means ERROR_SXS_ASSEMBLY_MISSING, indicating that a required side-by-side assembly file is missing from the Windows component store. This prevents cumulative updates from installing.

How do I fix Windows Cumulative Update Failure 0x80073701?

Run DISM and SFC scans to repair the component store, clear the SoftwareDistribution folder, and reset Windows Update components. If the error persists, perform a System Restore or in-place upgrade.

Can DISM fix error 0x80073701?

Yes, DISM is specifically designed to repair the component store. Running DISM /Online /Cleanup-Image /RestoreHealth is the most effective way to resolve this error.

Is it safe to delete the SoftwareDistribution folder?

Yes, it is safe. Windows will recreate it automatically. Deleting it forces fresh download of update files and can resolve corruption issues.

What is the difference between error 0x80073701 and 0x800f081f?

Both are component store corruption errors, but 0x80073701 specifically indicates a missing assembly, while 0x800f081f indicates a manifest or payload mismatch. Both are fixed with DISM and SFC.

Can third-party antivirus cause this error?

Yes, some antivirus software can block update processes. Temporarily disabling the antivirus may resolve the error.

How long does DISM take to fix error 0x80073701?

The DISM restore operation typically takes 15-20 minutes, depending on internet speed and system performance.

Will an in-place upgrade fix this error?

Yes, an in-place upgrade (repair install) will replace all system files and often resolves persistent update errors without losing personal data.

Can I fix this error with System Restore?

If the error started after a recent change, System Restore to a point before the issue can resolve it.

What should I do if the error persists after all fixes?

If all else fails, consider a clean installation of Windows. Back up your files, create installation media, and perform a fresh install to eliminate any system corruption.

HowToFixPro Editorial Team

We’re a team of system administrators, technical writers, and platform specialists who genuinely enjoy solving the problems most users find frustrating. From persistent Windows errors and Android sync failures to browser crashes and network drops — we’ve seen it all, and we document every fix properly. Our guides are built on official documentation, direct testing, and real troubleshooting experience. No filler, no guesswork — just reliable, step-by-step solutions you can trust.