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10 Tech How-To

Fix Microsoft 0x8007643 & Check 0x80070643

Guide 10-29555 · Updated · Step by step

This guide walks you through fixing the Microsoft 0x8007643 error, which typically appears during Windows Update or when installing certain drivers, and also shows you how to check for the related 0x80070643 error (often seen with .NET Framework or Defender updates). Both errors usually stem from corrupted update components, system file issues, or insufficient disk space. You’ll need administrator access to your Windows PC and a stable internet connection.

What You’ll Need

  • Administrator account on your Windows PC
  • Stable internet connection
  • At least 10 GB of free disk space (recommended for updates)
  • Patience – some steps take several minutes

Step-by-Step

  1. Run Windows Update Troubleshooter

    Go to Settings > System > Troubleshoot > Other troubleshooters (Windows 11) or Settings > Update & Security > Troubleshoot > Additional troubleshooters (Windows 10). Click Windows Update and then Run. Follow the prompts; this often auto-fixes common update issues.

  2. Check for 0x80070643 Error

    The 0x80070643 error is separate but often appears alongside 0x8007643. To check for it, open Settings > Windows Update and click Update history. Look for any failed updates with code 0x80070643. If present, note the update name (e.g., .NET Framework or Windows Defender).

  3. Free Up Disk Space

    Both errors can be caused by insufficient space. Open Settings > System > Storage and review what’s taking space. Use Storage Sense or manually delete temporary files, old downloads, or move files to an external drive. Aim for at least 10 GB free.

  4. Run System File Checker (SFC)

    Open Command Prompt as administrator (search “cmd”, right-click, “Run as administrator”). Type sfc /scannow and press Enter. Wait for the scan to complete – it may take 15-30 minutes. If it finds corrupted files, it will repair them automatically.

  5. Run DISM Tool

    In the same Command Prompt window, run DISM /Online /Cleanup-Image /RestoreHealth. This fixes Windows system image corruption. Allow it to finish (may take 20+ minutes). Restart your PC after.

  6. Reset Windows Update Components

    If the above doesn’t work, reset the update cache. Open Command Prompt as admin and run these commands one by one, pressing Enter after each:

    • 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

    Restart your PC and try Windows Update again.

  7. Manually Download the Update

    If the error persists for a specific update (like a .NET Framework update), go to the Microsoft Update Catalog (official site), search for the update KB number from the error, download the correct version for your system (x64 or x86), and install it manually.

  8. Perform a Clean Boot

    Sometimes third-party software interferes. Type msconfig in Run (Win+R). Under Services, check Hide all Microsoft services, then click Disable all. Under Startup, open Task Manager and disable all startup items. Restart and try updating again.

  9. Use Windows Update Assistant

    If all else fails, download the Windows Update Assistant from Microsoft’s official website. It forces the latest feature update and often bypasses stuck errors.

Common Mistakes

  • Skipping the Troubleshooter: Many users jump straight to complex fixes, but the built-in troubleshooter resolves a surprising number of cases.
  • Not running DISM after SFC: SFC repairs files, but DISM fixes the underlying image. Run both in order.
  • Deleting SoftwareDistribution without stopping services: If you try to rename or delete that folder while Windows Update is running, you’ll get an “access denied” error.
  • Ignoring disk space: Even if you think you have space, Windows Update needs room for temporary files. Check again.
  • Using third-party “fix” tools: Many are scams or cause more harm. Stick to official Microsoft methods.

Tips

  • Backup before major changes: Create a restore point (search “create a restore point”) before resetting update components.
  • Keep Windows updated regularly: Small updates are easier than big jumps; enable automatic updates.
  • Check for manufacturer driver updates: If the error occurs during a driver install, visit your PC manufacturer’s support site for the latest driver.
  • Use the Media Creation Tool as a last resort: It can upgrade Windows while keeping your files, but it’s a bigger step.

Troubleshooting

If the above steps don’t resolve the error:

  • Error persists after resetting components: Try the Windows Update Assistant or the Media Creation Tool (both from Microsoft) to perform an in-place upgrade.
  • 0x80070643 appears with .NET Framework: Uninstall the .NET Framework version from Settings > Apps > Installed apps, then reinstall it from the Microsoft website.
  • Check for malware: Run a full scan with Windows Defender (built-in) to rule out infections that may block updates.
  • Review event logs: Open Event Viewer > Windows Logs > System and look for errors around the time of the failed update. The details can give clues.
  • If nothing works: Consider a “Reset this PC” from Settings > System > Recovery, choosing “Keep my files”. This reinstalls Windows without losing personal data.

Frequently Asked Questions

What causes error 0x8007643?

It’s usually caused by corrupted Windows Update components, insufficient disk space, or a conflict with third-party security software.

Is 0x80070643 the same as 0x8007643?

No, they are different codes. 0x80070643 is often seen with .NET Framework or Windows Defender updates, while 0x8007643 is more generic. Both indicate update installation failures.

Will I lose my files if I reset Windows Update components?

No, renaming the SoftwareDistribution and Catroot2 folders only clears the update cache. Your personal files are untouched.

How long does the DISM command take?

It typically takes 15-30 minutes, but can be longer on older systems. Let it complete without interruption.

Can I fix these errors without admin access?

No, most steps require administrator privileges. If you’re on a work PC, contact your IT department.

Why does the error keep coming back after a week?

Recurring errors often indicate a deeper system issue, like failing hardware or a persistent malware infection. Run a full antivirus scan and check disk health with chkdsk /f in Command Prompt.

Related

General steps for current mainstream versions; menus can differ by device and version. See the disclaimer or report an error.

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