How to Fix Installing Windows Product Key Error 0x800F0805 on Windows 10?

Windows update is an essential component of MS Windows and in the same fashion, licensing your operating system or its update features is also a necessity. Error Code 0x800F0805 primarily occurs when Windows Product Key installation fails but it has also been noticed due to Windows Update Failures in general & also in cases when the user tries to switch to another version of Windows i.e., Home to Professional.

Installing Windows Product Key Error 0x800F0805 Notification

This error has been bugging many users as per reports submitted on online forums. The error prevents users from upgrading the operating system or licensing it. Windows update errors indicate that either the update is not appropriate for your computer or it might mean that your computer does not fulfill the minimum requirements to install the updates. All the security patches and feature updates are furnished to our PC via Windows updates. This error indicates the system failures, can cause damage and the PC becomes more vulnerable to bugs and viruses so this issue needs to be fixed ASAP. The user is notified as follows:

What Causes Installing Windows Product Key Error 0x800F0805?

This error can arise due to many reasons but most probably it appears when the windows installation key does not work out the way it should or the Windows updates. We have collected the most reported reasons behind the occurrence of this error depending upon the users’ feedback. The list of causes of this error are listed below:

  • Poor Internet Connection: It is obvious that if you are not having an active internet connection (good bandwidth), the Windows update/license installation process will show errors. Having limited internet access despite internet connection shows that there is a problem with your internet connection, not with the Windows update/installation key.
  • Inadequate Drive Space: In case this error code is because of Windows Updates failure then there is a strong possibility that your Windows drive (which is by default C drive) may not have enough space to install Windows updates, ultimately causing this error. Before finding a solution, make sure that you have at least 16GB and 20GB free space on your C drive for the 32-bit and 64-bit version of Windows 10 respectively.
  • Bugs in Update Delivery: Rarely the error comes up while installing the Windows updates due to the bugs in the updates delivered to your PC. This indicates that your system has no issues rather the Microsoft servers are facing problems due to some bugs.
  • Corrupt or Missing System Files: Corrupt operating system installation may lead to this cause, further leading to the Error under consideration. System files are essential to make sure smooth running of everything on your device. Sometimes your system files get corrupted or deleted which can cause Windows license/updates installation to fail. Another reason might be the damaged sections of your hard drive that might have viruses and malware.
  • Background Programs/Processes: Several applications start running automatically in the background such as anti-virus software and basic system processes when you start your PC. These services can cause obstacles in your aim to upgrade Windows to the latest version or install Windows updates, ultimately causing errors.
  • Outdated Drivers: Drivers are required to handle components that do not originally come with Windows 10 compatibility such as graphic cards, network cards, etc. If a driver has not been updated in a while, it can cause issues with Windows Update.
  • External Hardware Devices: Non-essential external hardware devices such as headphones, printers, scanners, USB flash drives, speakers, etc. may be causing the error 0x800F0805. You can also face this error if your PC is plugged into a docking station.
  • Accidental Sign-out: Windows update or upgrade errors may occur if you accidentally sign out or restart your PC. Try updating or upgrading again and make sure your PC remains on and plugged in.

Pre-Requisites:

Before heading toward the solutions, we will recommend you to follow the short steps and cross-checks to either solve the problem or minimize the causes of the error under consideration. All the possible steps are given below in detail:

  1. Repair Corrupt Files: To avoid the update installation error due to damaged system files, try to repair or restore them by the given steps:
    Open “Command Prompt” > type “DISM.exe /Online /Cleanup-image /Restorehealth” > press “Enter” on your keyboard.
    Then again in cmd, run the following command and press “Enter”: sfc/scannow
  2. Repair Hard-drive Errors: It is better to run a hard drive repair mechanism to eliminate this possible cause of the error. To repair the hard drive errors, follow these steps: Open “Command Prompt” > type “chkdsk/f C:” > Press “Enter”. After the repair is complete, you will be asked to restart your device.
  3. Unplug Extra Hardware: Remove all external storage devices such as drives, docks, or any hardware you might have plugged into your device that you are not using currently.
  4. Free Up Disk Space: As listed in the causes above, check your drive space according to the Windows bit version you are using and if you do not have enough disk space then you can free up space by reading this article.
  5. Run Malware Scan: Sometimes malware can halt the Windows update or upgrade process. Follow these steps to scan the system for malware: Windows Security>Virus and Threat Protection>Quick Scan.
  6. Disable Antivirus: To protect your device during the Windows upgrade or update installation it is recommended to use Windows Defender. Non-Microsoft antivirus software sometimes cause errors while Windows upgrade. You can uninstall them by following these steps:
    Open Control Panel > Programs >Programs and Features> “Select Installed Antivirus Program” > Uninstall >Yes.

Solution 1: Install Windows Product Key through Command Prompt

When you try to upgrade your Windows version from Home to Education or Professional, the error code 0x800F0805 pops up due to the manual initialization of the Windows License Product key. This is usually done by the following steps:  Settings > Update & Security > Activation. This happens because some background update utility comes in the way of Licensing the Windows operating system. To avoid this error, the product key should be added through Command Prompt which is an automation tool of the Windows operating system and it gets the job done in the safe environment (preventing any other background processes to intervene) commands. This proved to be helpful for many users online. Follow the steps given below to implement this solution:

  1. Click Start, search cmd, and select Run as administrator. This will open a confirmation window on your screen.
    Running CMD as Administrator
  2. Select Yes to confirm. This will now open Windows Command Prompt with admin privileges which is an automation tool in Windows operating system.
    Confirming Administrative Action
  3. Copy-paste the following command in the command prompt and press Enter on your keyboard. It will reveal a list of Windows editions to which you can upgrade from the current version. If the version for which you have the product key is on the list then, you do not have to do a completely new installation of Windows.
    Executing Command in Command Prompt
  4. Type the following command along with your 25 digits Windows Activation Product Key in the command prompt and press Enter on your keyboard. This command will initialize the product key for Windows activation by utilizing the SLMGR tool (Software Licensing Management Tool) from Microsoft.
    Initializing Windows Activation Product Key
  5. Now, Restart your PC to save the changes made to the system. This will also reset the Cache memory which will minimize possible minimal errors or failures.
  6. Now try upgrading your Windows, accessing the restricted features due to license. Everything should be working now and the error should be rectified. In case it’s not then there must many other possibilities such as Corrupted Windows Services, Never-ending Background Processes, etc. that are causing these errors. Solutions are given below to target every insight, so do not panic and keep following the procedure.

Solution 2: Run Windows Update Troubleshooter

Windows update troubleshooter tool is provided by Microsoft which automatically analyzes and fixes the issues with Windows updates installation. Normally, this is not a worthy solution to go with but in this specific case i.e., Error Code 0x800F0805, this proved to be a helpful solution as this error is a minor as compared to the other windows update errors. Windows Troubleshooter will also indicate whether there is a pending reboot that is keeping Windows from updating (which was the case for many people who encountered this problem). Follow the steps given below to run it:

  1. Click Start > Settings. A window will open that contains all major Window settings i.e. System, Devices, Network & Internet, etc.
    Opening Windows Settings
  2. Click Update & security. This will open a window that contains Windows update-related settings i.e., Windows Security, Backup, Troubleshoot, etc.
    Opening Windows Update & Security Settings
  3. Click Troubleshoot > Additional troubleshooter. This will take you to Windows troubleshooting options for different categories i.e., Internet Connections, Windows Update, Printer, etc.
    Opening Additional Troubleshoot Options
  4. Click Windows Update > Run the troubleshooter. This will run a Windows Update troubleshooter that will try to resolve things automatically. This includes checking system settings and files, searching for any corrupted ones, and then replace them with fresh downloads from the internet. This process may take a few minutes therefore, wait until it gets finished.
    Running Windows Update Troubleshooter
  5. Once the problem is rectified (or problems) then close the Windows Troubleshooter and restart your PC. This will save all the changes made to the system.
  6. Now try upgrading your Windows, accessing the restricted features due to license. Everything should be working now and the error should be rectified. In case it’s not then as stated before, it could be because of multiple reasons. These reasons are being tackled one by one in the solutions listed below.

Solution 3: Reset Windows Update Related Components

Windows Update errors may occur due to corrupted components. These components are comprised of folders, services, and temporary files that store Windows Update data or Cache memory. Resetting these components will eradicate any miscellaneous issues that could be causing the error under consideration. Many users were able to fix this problem by resetting their Windows components. Follow the steps given below to do so:

  1. Click Start, search cmd and select Run as administrator. This will open a confirmation window on your screen.
  2. Select Yes to confirm. This will now open Windows Command Prompt with admin privileges which is an automation tool in Windows operating system.
  3. Copy-paste the following commands one by one in the command prompt and press Enter on your keyboard. This set of commands will first stop all Windows update related components, also resetting any changes made to them by corrupted third-party software.
    net stop wuauserv
    net stop cypt
    Executing Commands in CMD
  4. Type Exit in the command prompt and press Enter on your keyboard. This will close the command prompt.
  5. Restart your PC. It will restart the services that were stopped by the command prompt in the previous step, also it will help Windows operating system to absorb the changes.
  6. Now try upgrading your Windows, accessing the restricted features due to license. Everything should be working now and the error should be rectified. In case it’s not then move to the next solution.

Solution 4: Reset Windows Update Service Using Batch File

Windows update error 0x800F0805 sometimes occurs when the Windows update database is corrupted or one or more services related to Windows update are not running due to numerous reasons. We have created a batch file that includes all Windows update components related commands in its script. Simply running this batch file will initiate all the commands to process one by one, resetting any recent Windows update or its whole trajectory as a fresh install. Since this is a complete package, many users were able to fix this problem by following this method. In simple terms, this batch will reset the Windows update services to troubleshoot the issue. This batch can be used in all Windows versions, running at any patch update. Follow the given steps to do so:

  1. Download the Batch file from here.
  2. Browse the downloaded file and run it. The set of commands will reset the Windows Update and its related services on your PC no matter which patch you are on.
    Executing the Batch File
  3. Restart your PC. It will restart the services that were stopped by the command prompt in the previous step and it will also help Windows operating system to absorb the changes.
  4. Now try upgrading your Windows, accessing the restricted features due to license. Everything should be working now and the error should be rectified. In case it’s not then move to the next solution.

Solution 5: Manually Download & Install Windows Updates

If the above solutions did not fix your problem then there are strong chances that Windows is having some connection problems with Microsoft servers for some unknown reason. This is why you are not being able to register your Windows properly or update it. In this case, download the latest Windows updates manually from the official Microsoft website and then install them. This method not only provides the users with full control over installing Windows updates but also facilitates them with the option of delaying the Windows updates installed. This will eradicate any connection failures due to corrupt system files and hence you will be able to register your Windows or update it after the job is done. This solution has positive feedback from many users online. To manually download & install Windows updates follow the given steps:

  1. Download the latest Windows 10 updates from the Official Microsoft Software Download Page by clicking Update now on the latest update patch option.
    Downloading the Latest Windows 10 Updates
  2. Run the downloaded file and click Yes on the pop-up window. This will open another window, click Accept to accept the Microsoft License and Agreements regarding Windows update setup.
    Accepting Microsoft Update License and Agreements
  3. Select Upgrade this PC now and click Next. This will take you to the next setup window.
    Upgrading Windows with the Latest Updates
  4. Click Accept again to agree to applicable notices and license terms.
    Accepting Applicable Notice & License Terms
  5. Finally, click Install. This will initialize the installation process that includes extracting packages, reading the information, and installing components.
    Initializing Windows Update Installation Process
  6. It might take a few minutes to install the latest Windows 10 updates and your PC may restart a few times during the process. Make sure not to turn off your computer in this timeline to avoid any errors. This solution will finally fix your problem.
    Installing the Latest Windows Updates

Kevin Arrows


Kevin is a dynamic and self-motivated information technology professional, with a Thorough knowledge of all facets pertaining to network infrastructure design, implementation and administration. Superior record of delivering simultaneous large-scale mission critical projects on time and under budget.

Expert Tip

How to Fix Installing Windows Product Key Error 0x800F0805 on Windows 10?

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