How to Fix Windows 11 Update Error 0x800f0983 (KB5066835 Failed)

Windows 11 update error 0x800f0983 usually appears when a cumulative update fails to install, most commonly KB5066835. The update may download successfully but fail during installation, even after multiple restarts. This issue is typically caused by corrupted update cache files, component store problems, or language pack mismatches.

What Is Windows 11 Error 0x800f0983?

Error 0x800f0983 is a Windows Update installation failure that occurs when the update process cannot properly apply system files. It is most often linked to cumulative updates, where even a small corruption can cause the entire update to fail.

Users usually experience:

• Repeated update failures
• “Installation failed” messages
• Update rollback after restart
• KB update stuck at installing stage

Why KB5066835 Fails to Install on Windows 11

The most common causes of error 0x800f0983 include:

• Corrupted SoftwareDistribution or Catroot2 folders
• Damaged Windows component store (WinSxS)
• Language or regional pack conflicts
• Interrupted downloads or power loss
• Incomplete previous update installations

Fix 1: Reset Windows Update Components

Corrupted update cache files are the most frequent reason for error 0x800f0983. Resetting Windows Update services clears blocked or damaged files.

Steps

1. Open Command Prompt (Admin)
2. Run the following commands one by one:

net stop wuauserv
net stop bits
net stop cryptsvc
del /s /q %windir%\SoftwareDistribution\*
del /s /q %windir%\System32\catroot2\*
net start wuauserv
net start bits
net start cryptsvc

3. Restart your PC
4. Go to Settings → Windows Update → Check for updates

Fix 2: Uninstall and Reinstall KB5066835 Manually

If the update installed partially, removing it before reinstalling often resolves the issue.

Steps

1. Open Command Prompt (Admin)
2. Run:

wusa /uninstall /kb:5066835

3. Restart your PC
4. Visit the Microsoft Update Catalog
5. Search for KB5066835
6. Download the correct .msu file for your system
7. Install it manually and restart

Fix 3: Run the Windows Update Troubleshooter

Windows includes a built-in troubleshooter that can automatically fix common update issues.

Steps

1. Open Settings
2. Go to System → Troubleshoot → Other troubleshooters
3. Click Run next to Windows Update
4. Apply recommended fixes
5. Restart your system

Fix 4: Clear Pending Update and Temporary Files

Leftover update files can block new installations.

Steps

1. Press Win + R
2. Paste:

C:\Windows\SoftwareDistribution\Download

3. Delete all files inside the folder
4. Go to:

C:\Windows\WinSxS\Temp

5. Delete Pending.xml if it exists
6. Restart and try updating again

Fix 5: Repair System Files Using DISM and SFC

If system files are corrupted, Windows Update will fail repeatedly.

Steps

1. Open Command Prompt (Admin)
2. Run:

DISM /Online /Cleanup-Image /RestoreHealth

3. After completion, run:

sfc /scannow

4. Restart your PC before checking for updates

Fix 6: Switch or Reinstall the Language Pack

Language pack mismatches are a known cause of error 0x800f0983.

Steps

1. Open Settings → Time & Language → Language & Region
2. Change Windows display language to English (United States)
3. Restart your PC
4. Install the update
5. Switch back to your preferred language after completion

Fix 7: Perform an In-Place Upgrade (Last Resort)

If none of the above fixes work, an in-place upgrade refreshes Windows system files without deleting personal data.

Steps

1. Download the Windows 11 Installation Assistant
2. Run the tool
3. Choose Upgrade this PC now
4. Complete the setup process

This method repairs system components and resolves persistent update errors like 0x800f0983.

FAQs Windows 11 Update Error 0x800f0983 (KB5066835 Failed)

What is Windows 11 error 0x800f0983?

Windows 11 error 0x800f0983 is an update installation failure that occurs when Windows cannot apply a cumulative update correctly. It usually appears during updates like KB5066835 and causes the update process to stop or roll back after restart.

Why does KB5066835 fail to install with error 0x800f0983?

KB5066835 fails due to corrupted Windows Update cache files, damaged system components, or language pack mismatches. In some cases, an interrupted update download or previous failed updates can also trigger error 0x800f0983.

Can Windows 11 error 0x800f0983 be fixed without reinstalling Windows?

Yes. In most cases, Windows 11 error 0x800f0983 can be fixed without reinstalling Windows. Resetting Windows Update components, running DISM and SFC scans, or manually reinstalling the update usually resolves the issue.

Is error code 0x800f0983 harmful to my PC?

No. Error code 0x800f0983 does not damage your PC or delete files. However, it prevents important security and stability updates from installing, which is why fixing it is strongly recommended.

Does changing the language pack fix error 0x800f0983?

Yes, switching the Windows display language to English (United States) has fixed error 0x800f0983 for many users. Language pack conflicts are a known cause of cumulative update failures in Windows 11.

What should I do if error 0x800f0983 keeps coming back?

If error 0x800f0983 keeps returning after multiple fixes, performing an in-place upgrade using the Windows 11 Installation Assistant is the most reliable solution. It repairs system files without removing personal data or apps.

Can I skip KB5066835 if it keeps failing?

Skipping KB5066835 is not recommended. Cumulative updates include critical security patches, and skipping them may leave your system vulnerable. Fixing Windows 11 error 0x800f0983 ensures your system stays fully updated and secure.

Windows 11 update error 0x800f0983 (KB5066835 failed) is usually caused by corrupted update files, system component issues, or language pack conflicts. By following the fixes above in order, most users can restore Windows Update functionality without reinstalling Windows.

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If the issue continues after all fixes, manually installing the update or performing an in-place upgrade is the safest solution.