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Windows Update Error 0x80070643: 11 Proven Ways to Fix It (2026)

Facing Windows Update Error 0x80070643? Learn 11 proven ways to fix it in 2026, from troubleshooting tools to system repairs, and get your updates running smoothly again.

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Table of Contents

  1. What Is Windows Update Error 0x80070643?
  2. Why Does Error 0x80070643 Happen?
  3. Quick Fixes You Should Try First
  4. Fix Recovery Partition Space Issues
  5. Repair .NET Framework
  6. Run Windows Update Troubleshooter
  7. Use System File Checker and DISM
  8. Reset Windows Update Components
  9. Disable Antivirus Temporarily
  10. Advanced Troubleshooting Methods
  11. Frequently Asked Questions

If you’re stuck staring at Windows Update error 0x80070643, you know how frustrating it can be. Your computer refuses to install important security updates, and you’re left wondering what went wrong.

The good news? You’re not alone, and this error is completely fixable.

I’ve helped hundreds of users resolve this issue, and in this guide, I’ll walk you through every solution that actually works. Whether you’re dealing with KB5034441, .NET Framework problems, or recovery partition issues, we’ve got you covered.

What Is Windows Update Error 0x80070643?

Windows update error 0x80070643 is a common installation failure that prevents Windows from completing updates. When it strikes, you’ll typically see one of these messages pop up on your screen:

“There were some problems installing updates, but we’ll try again later. If you keep seeing this and want to search the web or contact support for information, this may help: (0x80070643)”

Or you might encounter:

“Failed to install on [date] – 0x80070643”

This error code translates to ERROR_INSTALL_FAILURE in Windows terminology. Basically, something went wrong during the installation process, and Windows had to abort the update.

Which Updates Trigger This Error?

The 0x80070643 error can affect various types of updates:

  • Security updates (especially KB5034441 for Windows 10)
  • Windows Defender definition updates
  • .NET Framework updates
  • Windows Recovery Environment (WinRE) updates
  • Cumulative updates for Windows 10 and 11

The KB5034441 update, in particular, has caused widespread issues since January 2024. This Windows Recovery Environment update requires at least 250MB of free space in your recovery partition, which many systems simply don’t have.

Is Error 0x80070643 Dangerous?

Not immediately, but you shouldn’t ignore it. Failed updates mean your computer isn’t getting critical security patches. Over time, this leaves your system vulnerable to malware, viruses, and security exploits.

The longer you go without updates, the more exposed you become.

Also Read This: KB5001716: What This Windows Update Really Means for Your PC (2026 Guide)

Why Does Error 0x80070643 Happen?

Understanding the root cause helps you pick the right fix. Here are the most common reasons behind Windows update error 0x80070643:

Insufficient Recovery Partition Space

This is the number one culprit, especially for KB5034441. Windows 10 created recovery partitions around 500MB in size. But newer WinRE updates need at least 750MB to install properly.

When Windows tries to install an update that doesn’t fit, you get error 0x80070643.

Corrupted .NET Framework

The .NET Framework is essential for many Windows applications and updates. If it becomes corrupted or damaged, Windows updates that depend on it will fail with error code 0x80070643.

Damaged System Files

Corrupted or missing Windows system files can derail the entire update process. These files are critical for Windows Update to function correctly.

Windows Update Component Issues

Sometimes the Windows Update service itself gets misconfigured. Corrupted cache files, stuck processes, or service malfunctions can all trigger this error.

Antivirus Interference

Third-party antivirus programs like McAfee, Norton, or Avast can be overprotective. They might block legitimate Windows Update files, mistaking them for threats.

Previous Incomplete Updates

If a previous update failed partway through, it can leave your system in an inconsistent state. This makes subsequent updates more likely to fail.

Incorrect System Settings

Registry errors, wrong permissions on update folders, or misconfigured services can all contribute to update failures.

Quick Fixes You Should Try First

Before diving into complex solutions, let’s start with simple fixes that work surprisingly often.

Restart Your Computer

I know this sounds too simple to work, but seriously, try it. Many Windows update error 0x80070643 cases resolve themselves after a simple restart.

Here’s why it helps: Windows Update sometimes gets stuck in a temporary state. Restarting clears this state and gives the update process a fresh start.

How to restart properly:

  1. Save all your work and close applications
  2. Click Start → Power → Restart
  3. Wait for your computer to fully restart
  4. Go to Settings → Windows Update
  5. Click Check for updates

Try the Update Again

Sometimes Windows Update just needs another shot. After restarting, click the “Retry” button in Windows Update.

Microsoft’s servers occasionally have hiccups. Waiting a few hours and trying again can work when server-side issues were causing the problem.

Check Your Internet Connection

A shaky internet connection can corrupt download files, leading to installation failures. Make sure you have a stable, fast connection before updating.

Quick connection test:

  1. Open Command Prompt
  2. Type ping google.com and press Enter
  3. If you see “Request timed out” or packet loss, your connection needs attention

Free Up Disk Space

Windows Update needs breathing room. If your C: drive is nearly full, updates can fail.

Check your available space:

  1. Open File Explorer
  2. Right-click your C: drive
  3. Select Properties
  4. Make sure you have at least 10GB free

If you’re low on space, use Disk Cleanup to remove temporary files:

  1. Search for “Disk Cleanup” in the Start menu
  2. Select your C: drive
  3. Check boxes for items to delete
  4. Click OK

Fix Recovery Partition Space Issues

This fix specifically targets KB5034441 and other WinRE update failures. If your recovery partition is too small, you’ll need to resize it.

Understanding the Recovery Partition Problem

Windows 10 machines created between 2015-2020 typically have recovery partitions around 500-530MB. But KB5034441 needs at least 750MB (250MB more than most systems have).

When Windows tries to install this update, it runs out of space and throws error 0x80070643.

Check Your Recovery Partition Size

Before resizing, let’s see what you’re working with:

  1. Press Windows + X and select Disk Management
  2. Look for a partition labeled “Recovery Partition” (usually at the end of your drive)
  3. Note its size

If it’s less than 750MB, you need to expand it.

Method 1: Use Microsoft’s Official Instructions

Microsoft provides detailed steps for manually resizing your recovery partition. This method works if your recovery partition is located right next to your C: drive.

Warning: This process involves disk partitioning. Back up your important files first.

  1. Press Windows + X and select Windows PowerShell (Admin)
  2. Type reagentc /info and press Enter
  3. Note the Windows RE location (should show “Enabled”)
  4. Type reagentc /disable and press Enter
  5. Type diskpart and press Enter
  6. Type list disk and note your main disk number (usually Disk 0)
  7. Type select disk 0 (replace 0 with your disk number)
  8. Type list partition to see all partitions
  9. Identify your OS partition (usually the largest, labeled Primary)
  10. Type select partition [number] (replace with your OS partition number)
  11. Type shrink desired=250 minimum=250 and press Enter

This shrinks your C: drive by 250MB, creating unallocated space.

Now create a new, larger recovery partition:

  1. Type list partition again
  2. Select your old recovery partition: select partition [number]
  3. Delete it: delete partition override
  4. Create a new recovery partition:
    • For GPT disk: create partition primary id=de94bba4-06d1-4d40-a16a-bfd50179d6ac
    • For MBR disk: create partition primary id=27
  5. Format it: format quick fs=ntfs label="Windows RE tools"
  6. For GPT, set attributes: gpt attributes=0x8000000000000001
  7. Type exit to close diskpart
  8. Re-enable Windows RE: reagentc /enable

Method 2: Use Third-Party Partition Software

If the manual method seems too risky, use a partition manager like AOMEI Partition Assistant or MiniTool Partition Wizard.

These tools provide a visual interface that’s much easier to understand:

  1. Download and install AOMEI Partition Assistant (free version works fine)
  2. Open the program
  3. Right-click your C: drive
  4. Select Resize/Move Partition
  5. Drag the slider to shrink C: drive by 500MB
  6. Click OK
  7. Right-click your Recovery partition
  8. Select Resize/Move Partition
  9. Extend it into the unallocated space
  10. Click Apply in the top-left corner

The software will restart your computer and resize the partitions safely.

After Resizing: Install the Update

Once your recovery partition is 750MB or larger:

  1. Open Settings
  2. Go to Windows Update
  3. Click Check for updates
  4. The KB5034441 update should now install successfully

Repair .NET Framework

A corrupted .NET Framework is one of the most common causes of Windows Update error 0x80070643. Fortunately, Microsoft provides an official repair tool.

Download the .NET Framework Repair Tool

Microsoft’s .NET Framework Repair Tool automatically detects and fixes common problems:

  1. Visit the Microsoft Download Center
  2. Click Download
  3. Run the downloaded file (NetFxRepairTool.exe)
  4. Accept the license agreement
  5. Click Next

The tool will scan your system for .NET Framework issues.

Run the Repair Process

Once the scan completes:

  1. Review the detected issues
  2. Click Next to apply recommended fixes
  3. Wait for the repair to complete (usually 5-10 minutes)
  4. Click Finish
  5. Restart your computer

After restarting, try Windows Update again. The error should be resolved if .NET Framework was the culprit.

Install the Latest .NET Framework

If the repair tool doesn’t work, try installing the newest .NET Framework version:

  1. Go to the .NET Framework download page
  2. Download the latest version (currently 4.8)
  3. Run the installer
  4. Follow the on-screen prompts
  5. Restart your computer

This fresh installation often fixes stubborn corruption issues.

Run Windows Update Troubleshooter

Windows includes a built-in troubleshooter specifically designed to fix update problems, including error 0x80070643.

Access the Troubleshooter in Windows 11

  1. Press Windows + I to open Settings
  2. Click System in the left sidebar
  3. Scroll down and click Troubleshoot
  4. Select Other troubleshooters
  5. Find Windows Update in the list
  6. Click the Run button next to it

The troubleshooter will start scanning for issues.

Access the Troubleshooter in Windows 10

  1. Press Windows + I to open Settings
  2. Click Update & Security
  3. Select Troubleshoot from the left menu
  4. Click Additional troubleshooters
  5. Select Windows Update
  6. Click Run the troubleshooter

Let the Troubleshooter Work

The Windows Update Troubleshooter will:

  • Check Windows Update service status
  • Verify update component integrity
  • Repair corrupted update files
  • Reset update configurations
  • Fix common permission issues

This process typically takes 2-5 minutes. The troubleshooter will show you what it found and fixed.

After it completes, restart your computer and try updating again.

What If the Troubleshooter Fails?

Sometimes the troubleshooter can’t fix everything automatically. If it reports “Couldn’t identify the problem,” don’t worry. Move on to the next solutions in this guide.

Use System File Checker and DISM

Corrupted system files are a major cause of Windows update error 0x80070643. Windows provides two powerful tools to fix them: SFC (System File Checker) and DISM (Deployment Image Servicing and Management).

Run System File Checker First

SFC scans all protected system files and replaces corrupted versions with cached copies.

Here’s how to run it:

  1. Press Windows + X and select Windows Terminal (Admin) or Command Prompt (Admin)
  2. If prompted by User Account Control, click Yes
  3. Type this command and press Enter:
sfc /scannow

The scan will take 10-15 minutes. You’ll see a progress percentage that updates slowly.

Possible results you might see:

  • “Windows Resource Protection did not find any integrity violations” – Your system files are fine. Skip to the next solution.
  • “Windows Resource Protection found corrupt files and successfully repaired them” – Great! Restart and try Windows Update.
  • “Windows Resource Protection found corrupt files but was unable to fix some of them” – You need DISM. Continue below.

Run DISM to Fix Deeper Issues

If SFC couldn’t repair everything, DISM can fix the underlying Windows image that SFC uses.

Run DISM with these commands:

  1. In the same admin Command Prompt, type:
DISM /Online /Cleanup-Image /CheckHealth

This quickly checks if the image is corrupted.

  1. If problems are found, run:
DISM /Online /Cleanup-Image /ScanHealth

This performs a more thorough scan (takes 5-10 minutes).

  1. Finally, repair the image:
DISM /Online /Cleanup-Image /RestoreHealth

This command can take 15-30 minutes. Don’t interrupt it even if it seems stuck.

After DISM: Run SFC Again

Once DISM finishes:

  1. Run SFC one more time: sfc /scannow
  2. This time it should successfully repair any remaining issues
  3. Restart your computer
  4. Try Windows Update again

Reset Windows Update Components

When Windows Update itself gets corrupted, you need to reset its components. This clears the update cache and resets all related services.

Stop Windows Update Services

First, we’ll stop all services related to Windows Update:

  1. Press Windows + X and select Command Prompt (Admin) or PowerShell (Admin)
  2. Enter these commands one by one, pressing Enter after each:
net stop wuauserv
net stop cryptSvc
net stop bits
net stop msiserver

These commands stop:

  • Windows Update service (wuauserv)
  • Cryptographic Services (cryptSvc)
  • Background Intelligent Transfer Service (bits)
  • Windows Installer (msiserver)

Rename Update Folders

Now we’ll rename the folders where Windows stores update files:

ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
ren C:\Windows\System32\catroot2 Catroot2.old

This forces Windows to create fresh folders with clean update data.

Restart Update Services

Start everything back up:

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

Try Updating Again

  1. Close Command Prompt
  2. Go to Settings → Windows Update
  3. Click Check for updates

Windows will recreate the necessary folders and download updates fresh. The error 0x80070643 should be gone.

Disable Antivirus Temporarily

Third-party antivirus software can interfere with Windows Update, causing error 0x80070643. Temporarily disabling it can help identify if it’s the problem.

Disable Third-Party Antivirus

If you use software like Norton, McAfee, Avast, or AVG:

  1. Right-click the antivirus icon in your system tray
  2. Look for options like “Disable,” “Turn Off,” or “Pause Protection”
  3. Select to disable for 15 minutes or 1 hour
  4. Confirm your choice

Important: Only disable antivirus on a trusted, private network. Don’t browse the web while it’s off.

Try Windows Update

With antivirus disabled:

  1. Go to Settings → Windows Update
  2. Click Check for updates
  3. Let the update install completely

If it works, your antivirus was blocking the update.

Re-enable Your Antivirus

Once the update completes:

  1. Right-click the antivirus icon again
  2. Select “Enable” or “Turn On Protection”

Then add Windows Update folders to your antivirus exclusion list to prevent future conflicts:

  • C:\Windows\SoftwareDistribution
  • C:\Windows\System32\catroot2

Windows Defender Considerations

Sometimes, even Windows Defender can cause issues. To reset it:

  1. Open Settings → Apps
  2. Click Apps & features
  3. Search for “Windows Security”
  4. Click it, then click Advanced options
  5. Scroll down and click Repair

This refreshes Windows Defender without disabling your protection.

Advanced Troubleshooting Methods

If none of the basic fixes worked, these advanced solutions might do the trick.

Perform a Clean Boot

A clean boot starts Windows with minimal drivers and startup programs, eliminating software conflicts.

How to perform a clean boot:

  1. Press Windows + R to open Run
  2. Type msconfig and press Enter
  3. Click the Services tab
  4. Check Hide all Microsoft services
  5. Click Disable all
  6. Click the Startup tab
  7. Click Open Task Manager
  8. Disable each startup item by right-clicking and selecting Disable
  9. Close Task Manager
  10. Click OK in System Configuration
  11. Restart your computer

Now try Windows Update. If it works, one of the disabled services or programs was causing the problem.

To identify which one:

  1. Re-enable services/programs one by one
  2. Restart and test Windows Update after each
  3. When the error returns, you’ve found the culprit

Manually Download and Install the Update

If Windows Update keeps failing, grab the update manually from Microsoft Update Catalog:

  1. Visit Microsoft Update Catalog
  2. Search for the KB number from your error message (e.g., “KB5034441”)
  3. Download the version matching your Windows edition (x64 or x86)
  4. Double-click the downloaded .msu file to install
  5. Follow the installation prompts
  6. Restart when prompted

This bypasses the Windows Update system entirely.

Check Disk for Errors

Disk errors can corrupt update files. Run a disk check:

  1. Open File Explorer
  2. Right-click your C: drive
  3. Select Properties
  4. Click the Tools tab
  5. Under “Error checking,” click Check
  6. Click Scan drive

If errors are found, restart your computer to let Windows fix them.

Reset Windows Update Database

For stubborn cases, completely reset the Windows Update database:

  1. Stop Windows Update services (as shown earlier)
  2. Delete these folders completely:
    • C:\Windows\SoftwareDistribution
    • C:\Windows\System32\catroot2
  3. Restart Windows Update services
  4. Reboot your computer

Windows will rebuild everything from scratch.

Use System Restore

If the error started recently, System Restore can roll back changes:

  1. Search for “Create a restore point” in Start menu
  2. Click System Restore
  3. Click Next
  4. Choose a restore point from before the error started
  5. Click Next then Finish

Your computer will restart and restore to that state.

When All Else Fails: Consider a Repair Install

If you’ve tried everything and windows update error 0x80070643 persists, a repair install might be your best option.

What Is a Repair Install?

A repair install reinstalls Windows while keeping your files, apps, and settings intact. It’s less drastic than a clean install but more thorough than normal troubleshooting.

How to Perform a Repair Install

  1. Download the Windows 10 Media Creation Tool or Windows 11 Installation Assistant
  2. Run the downloaded tool
  3. Accept the license terms
  4. Select Upgrade this PC now
  5. Choose Keep personal files and apps
  6. Follow the prompts to complete installation

The process takes 30-60 minutes. Your files and most programs will remain intact, but you’ll get fresh Windows system files.

After the Repair Install

  1. Go to Settings → Windows Update
  2. Install any pending updates
  3. The error 0x80070643 should be resolved

Preventing Future Update Errors

Once you’ve fixed error 0x80070643, follow these tips to prevent it from returning:

Keep Your System Maintained

  • Run Disk Cleanup monthly to remove temporary files
  • Use CCleaner or similar tools to clean your registry
  • Keep at least 15GB free on your C: drive
  • Restart your computer at least once a week

Update Regularly

Don’t let updates pile up. Install them as they become available. This prevents compatibility issues between old and new updates.

Monitor Your Recovery Partition

If you had to resize it, check it periodically:

  1. Open Disk Management
  2. Verify your recovery partition is still 750MB+
  3. If it shrinks, resize it again before issues occur

Use Windows Update Assistant

For major updates, use the Windows Update Assistant instead of Windows Update:

  1. Download it from Microsoft’s website
  2. Run it to install feature updates smoothly
  3. This often avoids errors that plague Windows Update

Keep Antivirus Updated but Configured

Make sure your antivirus is current, but add Windows Update folders to its exclusion list:

  1. Open your antivirus settings
  2. Find “Exclusions” or “Exceptions”
  3. Add: C:\Windows\SoftwareDistribution and C:\Windows\System32\catroot2

Frequently Asked Questions About Windows Update Error 0x80070643

What is Windows update error 0x80070643?

Windows update error 0x80070643 is an installation failure that prevents Windows from completing security updates, .NET Framework updates, or Windows Recovery Environment updates. It typically indicates corrupted files, insufficient disk space, or .NET Framework problems.

How do I fix error code 0x80070643 on Windows 10?

The most effective fixes are resizing your recovery partition to 750MB, running the .NET Framework Repair Tool, using System File Checker (sfc /scannow), running Windows Update Troubleshooter, and resetting Windows Update components. Start with simple solutions like restarting your computer before trying advanced methods.

Is error 0x80070643 related to KB5034441?

Yes, KB5034441 is the Windows Recovery Environment update that commonly triggers error 0x80070643. This happens because the update requires at least 250MB of free space in your recovery partition, which most Windows 10 systems don’t have by default.

Can I ignore Windows update error 0x80070643?

You shouldn’t ignore this error for extended periods. Failed updates mean your system isn’t getting critical security patches, leaving it vulnerable to malware and exploits. However, if the only failing update is KB5034441 and you don’t use Windows Recovery Environment, Microsoft says you can safely ignore it until they release a fix.

How much space does the recovery partition need?

Microsoft recommends at least 750MB for the recovery partition to accommodate WinRE updates like KB5034441. Older Windows 10 installations typically have 500-530MB recovery partitions, which aren’t large enough.

Will resizing the recovery partition delete my data?

When done correctly, resizing the recovery partition shouldn’t delete your personal data. However, you should always back up important files before making any partition changes. The process deletes the old recovery partition and creates a new one, but your C: drive data remains untouched.

Does error 0x80070643 affect Windows 11?

Yes, error 0x80070643 can occur on both Windows 10 and Windows 11. The causes and fixes are similar across both operating systems, though Windows 11 generally has larger default recovery partitions.

How long does the .NET Framework Repair Tool take?

The Microsoft .NET Framework Repair Tool typically takes 5-10 minutes to scan and repair your .NET Framework installation. Complex issues might take up to 15 minutes. Your computer will need to restart after the repair completes.

Can antivirus software cause error 0x80070643?

Yes, third-party antivirus programs like Norton, McAfee, Avast, and AVG can interfere with Windows Update files and cause error 0x80070643. Temporarily disabling your antivirus during updates or adding Windows Update folders to the exclusion list can resolve this.

What should I do if System File Checker finds errors it can’t fix?

If SFC reports “Windows Resource Protection found corrupt files but was unable to fix some of them,” run the DISM tool with the command DISM /Online /Cleanup-Image /RestoreHealth. After DISM repairs the Windows image, run SFC again to fix the remaining corrupted files.

Is it safe to manually delete the SoftwareDistribution folder?

It’s safe to rename or delete the SoftwareDistribution folder while Windows Update services are stopped. Windows will automatically recreate this folder with fresh update data. Always stop the wuauserv service first net stop wuauserv before modifying this folder.

Will a clean install fix error 0x80070643?

A clean install will definitely fix error 0x80070643, but it’s overkill for this problem. Try the simpler solutions first. If you must reinstall Windows, use a repair install (upgrade install) instead, which keeps your files and apps while refreshing system files.

Conclusion: Getting Past Error 0x80070643

Windows update error 0x80070643 is frustrating, but it’s almost always fixable without resorting to extreme measures like reinstalling Windows.

Start with the simple solutions: restart your computer, run Windows Update Troubleshooter, and repair your .NET Framework. These three steps alone resolve the error for most users.

If you’re specifically dealing with KB5034441, the recovery partition resize is your best bet. Yes, it’s a bit technical, but the step-by-step instructions above make it manageable even for beginners.

For stubborn cases, the combination of SFC, DISM, and resetting Windows Update components will handle nearly everything else.

Remember, keeping your Windows system updated is crucial for security. Don’t put off these fixes—your computer’s protection depends on those updates installing successfully.

Have you successfully fixed error 0x80070643 using one of these methods? Or are you still stuck? Drop a comment below and let me know which solution worked for you, or ask if you need help with a specific step.

Stay updated, stay secure, and happy computing!

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