How to fix
Windows update error 0x80070306
on Windows

Windows 11 cumulative update won't install for me because it constantly fails after trying for a long time. I am trying to install it for weeks to no avail. The error code produced is 0x80070306.

Windows update error 0x80070306 is a very frequent issue experienced by users while installing cumulative or feature updates on their computers. Generally, this type of error appears when the update process is not successful and puts the system in its pre-update condition, usually with a notification that states, "Some updates failed to install."

This generally becomes a frustrating issue for users who are dependent on timely updates for performance enhancements, bug fixes, and application of security patches.

Users often report error code 0x80070306 in reports during installation of Windows 11, Windows 10 updates, including cumulative updates and security patches.

For example, users have been registering opinions in forums that indicate their system keeps failing to install the updates, with this particular error code popping up over and over in the update history or logs. Such incidents would eventually lead to repeated prompts of updates that never get successfully done and thus will create a loop of failed attempts.

The root causes of error 0x80070306 can vary but are generally linked to issues with system files, update components, or conflicting software. Corrupted Windows Update components, incomplete update downloads, or conflicts with third-party antivirus programs are common triggers. Additionally, problems with the Windows Update service or misconfigured system settings may also result in this error.

Symptoms include failure to download or install updates, update progress getting stuck at a certain percentage, or error messages in the Windows Update settings. Some users report experiencing sluggish performance or seeing additional errors in the Event Viewer, further complicating the troubleshooting process.

While resolving error 0x80070306 may involve a mix of simple and advanced techniques, such as repairing corrupted system files or resetting update components, identifying the exact cause is often key. Instructions for addressing the issue are provided below for those who wish to fix it manually.

For an efficient, automated approach to resolving Windows issues, the [d1] repair app is an excellent option, offering quick diagnosis and resolution for update-related problems.

Fix 1. Use "Fix problems using Windows Update" feature

According to some users, using this built-in feature managed to help to fix the 0x80070306 error.

• Right-click on Start and pick Settings.
• Go to the System section and select Recovery.
• There, you should see the Fix problems using Windows Update option.
• Click Reinstall now.
• Follow the on-screen instructions to finish the process.
• After your PC restarts and the fix process is complete, attempt to update Windows in a usual way.

Fix 2. Run the Windows Update troubleshooter

Windows includes a built-in troubleshooter specifically designed to identify and fix update-related issues.

• Type Troubleshoot in Windows search and hit Enter.
• Select Additional troubleshooters/Other troubleshooters.
• Find Windows Update from the list and select Run the troubleshooter/Run.
• Wait till the scan is finished - you will be provided with potential causes so you can proceed with fixes.

Fix 3. Reset Windows Update components

Corrupted update components can prevent updates from installing. Resetting these components can resolve many update errors.

• Type cmd in Windows search.
• Right-click on the Command Prompt result and select Run as administrator.
• When the UAC window pops up, click Yes.
• Paste each of these commands, pressing Enter after each:
  net stop bits
  net stop wuauserv
  net stop appidsvc
  net stop cryptsvc
  Del “%ALLUSERSPROFILE%\Application Data\Microsoft\Network\Downloader\*.*”
  rmdir %systemroot%\SoftwareDistribution /S /Q
  rmdir %systemroot%\system32\catroot2 /S /Q
  regsvr32.exe /s atl.dll
  regsvr32.exe /s urlmon.dll
  regsvr32.exe /s mshtml.dll
  netsh winsock reset
  netsh winsock reset proxy
  net start bits
  net start wuauserv
  net start appidsvc
  net start cryptsvc 
• Restart your computer.

Fix 4. Run SFC and DISM scans

Corrupted system files may cause update errors - you can address this by using specific commands in elevated Command Prompt.

• Open Command Prompt as administrator.
• Type in the following command and press Enter:
  sfc /scannow
• When done, run the following commands as well:
  dism /online /cleanup-image /scanhealth
  dism /online /cleanup-image /checkhealth
  dism /online /cleanup-image /restorehealth
  (Note: if you get an error executing this last command, add /Source:C:\RepairSource\Windows /LimitAccess to it and try again).
• Restart your computer.

Fix 5. Disable third-party antivirus

Overprotective antivirus programs can block updates. Temporarily disabling your antivirus can help determine if it's the cause.

• Right-click the antivirus icon in your system tray.
• Select Disable or Pause protection.
• Choose the option to disable it temporarily (e.g., for 15 or 30 minutes).
• Retry the update process.

Fix 6. Free up disk space

Updates may fail if your system drive does not have sufficient space. Freeing up storage ensures updates have the required room to install.

• Type Disk Cleanup in Windows search and press Enter.
• In the Disk Cleanup window, select the drive where your Windows operating system is installed (usually drive C:) and click OK.
• Click Clean up system files.
• Select the drive again and click OK.
• In the list of files that can be cleaned up, select the largest portions of data, such as Temporary Internet Files, Windows Update, Temporary Files, and others.
• Click OK to begin the cleanup process.

Fix 7. Manually download and install the update

If automatic updates fail, manually installing the update can bypass certain issues.

• Type in Updates in Windows search and press Enter.
• Select View update history.
• Find the update that failed with the 0x80070306 error and copy its KB number.
• Open your browser and go to Microsoft Update Catalog.
• Within the search bar, type in the KB number and clicks Search.
• Find the correct version of the update for your operating system (to check this, right-click on Start and pick System. Under Device specifications and check the System type) and click Download.
• Use on-screen guidelines to finish the installation process and restart your system.

Fix 8. Perform an in-place upgrade

An in-place upgrade repairs your system while retaining your files and settings.

• Visit the official Microsoft website and download Windows 10 installation media (Windows 11 version).
• Double-click the installer, select Yes when UAC shows up, and agree to the terms.
• Select Upgrade this PC now and click Next.
• Windows will start downloading the needed files.
• Agree to the terms once again and click Next.
• Before installing, make sure that you are happy with your choices (otherwise, you can click Change what to keep option).
• Finally, click Install to begin the upgrade process.