Troubleshooting Product Key Error 0x800F0805 in Windows 10

If you received error code 0x800f0805 during activation when upgrading Windows to a new version, such as Professional to Enterprise or Home to Professional, this article will help you. The error can also occur when upgrading Windows. We will tell you the best possible solution to fix the problem.

Depending on the situation in which you received error 0x800f0805, follow the guidelines below to solve the problem. While the activation problem can be easily solved, the update error can be difficult to deal with.

What causes the product key error 0x800F0805?

  • Damaged or missing system files: Improper installation of the operating system can cause this, which in turn leads to this error. System files are important to ensure that your device works properly. Sometimes system files get corrupted or deleted, which can cause Windows license/update installation to fail. Another reason may be corrupted areas of your hard drive that may be infected with viruses and malware.
  • Not enough disk space: If this error code is associated with a Windows update installation error, there is a possibility that the Windows drive (default C drive) does not have enough space to install Windows updates, which eventually leads to this error. Before looking for a solution, make sure you have at least 16 GB and 20 GB of free space on your C drive for 32- and 64-bit versions of Windows 10, respectively.
  • Poor Internet connection: Obviously, the Windows update/license installation process will display errors if you do not have an active Internet connection (good bandwidth). Limited Internet access despite having an Internet connection indicates that the problem is with your Internet connection and not with the Windows upgrade/installation key.
  • Update installation error: In rare cases, the Windows update installation error is due to errors in the updates supplied to your computer. This indicates that there is no problem with your system, but Microsoft’s servers are having problems due to errors.
  • Outdated drivers: Drivers are needed to run components not originally compatible with Windows 10, such as video cards, network cards, etc. If the driver has not been updated for some time, this may cause problems with Windows Update.
  • Major programs/processes: Some applications run automatically in the background, such as antivirus software and major system processes when you start your computer. These services can prevent you from updating Windows to the latest version or installing Windows updates, which ultimately causes errors.

How to resolve the product key error 0x800F0805?

Launch the Windows troubleshooter

  1. Press Windows + I to open Windows 10 settings.
  2. Navigate to “Update and Security” and click on it.
  3. Move down the left side to Troubleshooting and select it to open the section on the right.
  4. Now click on Windows Update and follow the instructions.
  5. Then reboot the system and check if the problem is fixed.

The first thing you should do when you encounter any problem with Windows Update is to consult the built-in troubleshooting utility. This feature can detect and fix various problems on your computer.

Perform an SFC/DISM Scan

  1. Open the Run dialog box by pressing Windows + R at the same time.
  2. Type “cmd” (without the quotes) in the search box and press Ctrl + Shift + Enter to open the Administrator Command Prompt.
  3. When prompted by User Account Control (UAC), click Yes to grant administrator rights.
  4. Now at the extended command prompt, type the following command line and press Enter.
    sfc /scannow
  5. Leave the process for a while and reboot the system when it is complete.
  6. The next time you restart, open the Administrator: Command Prompt window again, as described in steps 1 and 2.
  7. Insert the following command line before you press Enter.
    DISM.exe /Online /Cleanup-image /Restorehealth
  8. As mentioned earlier, your system must be connected to a stable network for this process to work.
  9. Allow the process to run. This can take up to 15 minutes.
  10. Then reboot your computer and check to see if the problem has been resolved.

System File Checker (SFC) is another useful built-in Windows 10 utility that checks system files for corrupt or missing copies and replaces them with healthy ones. SFC uses a local cache to restore new copies and replace corrupted copies. DISM retrieves its fresh copies from an online server to replace corrupt or faulty system files.

Manually download and install system updates

  1. Press Windows + I to open Windows 10 settings.
  2. Select the System tab, then scroll down to find the About option.
  3. Under Device Specifications, find the System Type section and note whether your PC is running on 64-bit or 32 bit OS.
  4. Now go back to the main Windows 10 settings window and this time select Update and Security.
  5. Check for pending updates and make a note of the update code. It might be KB4078407, for example.
  6. Click this link to access the Microsoft Update Catalog.
  7. Use the specified update code to locate the specific update file.
  8. Download the update according to the version of your system.
  9. After you download the file with a .msu extension, double-click it to begin the installation.
  10. Then restart your system to make the new update take effect.

Windows 10 users can download the latest system updates from the Microsoft Update directory and then install them manually as a workaround to fix error 0x800f0805.

Frequently Asked Questions

  1. Examine the Windows update processes.
  2. Run DISM.
  3. Run SFC.
  4. Reset the Windows Update components.
  5. Reboot your computer.
  6. Force a new Windows Update download.
  7. Prevent websites, ISPs, and other parties from tracking you.
  8. Quick recovery of lost files.

Windows Update Error 0x800f0805 occurs when you update your version of Windows. Upgrading from Professional to Enterprise or from Home to Professional will cause this problem. Microsoft regularly releases updates and patches for the Windows operating system.

  1. Run the Windows Update troubleshooter.
  2. Use the DISM tool.
  3. Run an SFC scan.
  4. Reset the update components.
  5. Use the Windows Media Creation tool.
  6. Manually download and install updates.
  7. Reboot your computer.

The error occurs when you go to Settings > Update and Security > Activation. Try to activate Windows with a new key. Then run dism /online /get-targeteditions and you will get a list of Windows editions to upgrade from the current version.

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Mark Ginter is a tech blogger with a passion for all things gadgets and gizmos. A self-proclaimed "geek", Mark has been blogging about technology for over 15 years. His blog,, covers a wide range of topics including new product releases, industry news, and tips and tricks for getting the most out of your devices. If you're looking for someone who can keep you up-to-date with all the latest tech news and developments, then be sure to follow him over at Microsoft.