It is not unusual to encounter an error when trying to activate Windows on your computer. There are several possible reasons why this could happen. Most often the error message would say “The product key you entered didn’t work” or “We can’t activate Windows on this device because you don’t have a valid digital license or product key.“
Unfortunately, these error messages are mostly misleading. Often times they are false negatives and do not actually reflect the validity of the license you entered. Fortunately though, they always have an Error Code associated with them. These are the 10-character alphanumericis code found at the end of the error message as shown in the figure below. These codes help to provide more accurate information about the error and the possible causes. They also provide experts and troubleshooters better information to work with.

Below are the most common Windows 10 activation errors, their causes, and how to fix them respectively. If the error you received has not been listed below or you have tried the recommended fixes below and the error continues, please contact our support team directly via email for quick help (info@primetechmart.com).
1. Error Code: 0xc004f050

Error Message: “The product key that you entered didn’t work. Check the product key and try again, or enter a different one. (0xc004f050) “
Causes of Error:
- This error mostly happens because the activation servers were busy at the time you tried to activate your Windows. It could also happen when you enter an invalid product key. You can read more about this error from this article on the Microsoft Support page.
- This error could also happen if you’re trying to activate the wrong Windows edition.
How to Fix:
- First, double-check that you are entering the key correctly. If you’re sure that the key was entered correctly, then wait for a few hours, restart your computer and try the activation again. The idea is to wait for the activation servers to be less busy. Restarting your computer allows it to re-establish a fresh connection with the servers. This improves the chances of successful activation.
- Check that you’re not trying to activate the wrong edition of Windows. If the license you have bought is for activating Windows 10 Pro, but you’re trying to activate Windows 10 Pro N (Different from Windows 10 Pro) or Windows 10 Enterprise, or Windows 10 Home, then you can encounter this error. Same applies if you’re trying to use Windows 10 Home license to activate Windows 10 Home N (Different from Windows 10 Home), Windows 10 Pro, or Windows 10 Enterprise. To fix this, you need to first install Windows 10 Pro or Home depending on which license you purchased, then do the activation afterwards.
If you still can’t activate your Windows, please contact our support team (info@primetechmart.com) for a quick help.
2. ERROR CODE: 0x800f0805

Error Message: “The product key that you entered didn’t work. Check the product key and try again, or enter a different one. (0x800f0805) “
Causes of Error: This error mostly happens
How to Fix: Simply restart your computer, connect to the Internet and run Windows updates. Allow any new updates to fully download and install. After installing all the new updates, it should either restart automatically or you can restart manually and wait for any post-boot updates to fully install. Afterwards, now make the activation again, it should work fine.
NB. If for some reason updates are not downloading and installing accordingly on your computer, then it is not possible to upgrade your Windows 10 Home to Pro because is through updates that the upgrade is done. So, first check your settings and ensure your updates settings are proper for downloading and installing updates before you continue with the upgrade.
Restarting your computer allows it to re-establish a new connection with the servers, which puts it in a better state for a successful activation.
If the error continues, here’s another possible solution:
- Search for Command Prompt, right-click, and click “Run as administrator.”
In the command line prompt, type the following line to enter your product key through the command prompt:
slmgr.vbs /ipk
For example:
slmgr.vbs /ipk 12345-ABCDE-67890-FGHIJ-12345
- If it works for you, it will say your product key was entered properly! You can check the Activation tab in settings to verify the change was implemented.
If you still can’t activate your Windows, please contact our support team (info@primetechmart.com) for a quick help.
3. ERROR CODE: 0x803f7001

Error Message: “We can’t activate Windows on this device because you don’t have a valid digital license or product key. If you think you do have a valid license or key, select Troubleshoot below. (0x803f7001) “
Causes of Error: This error mostly happens for one of the following reasons:
- You are trying to activate the wrong edition of Windows 10.
- You changed the hardware (Motherboard or hard disk) on a previously activated Windows 10 PC.
You can read more about this error from this article on the Microsoft support page.
How to Fix:
- For the case of trying to activate the wrong edition of Windows. If the license you have bought is for activating Windows 10 Pro, but you’re trying to activate Windows 10 Pro N (Different from Windows 10 Pro) or Windows 10 Enterprise, or Windows 10 Home, then you will encounter this error. To fix this, you need to first install Windows 10 Pro, then do the activation afterwards.
- For the case of hardware changes, i.e. If your PC was recently repaired at an independent repair facility, or you changed your hard disk, your motherboard, your BIOS chip, or other major hardware components, then is likely that you will require a new Windows 10 license.
If the error continues and you have verified that none of the two scenarios above is applicable to your case, then please contact our support team (info@primetechmart.com) for a quick help.
4. Error CODE: 0x803fa067

Error Message: “We can’t activate Windows on this device because you don’t have a valid digital license or product key. If you think you do have a valid license or key, select Troubleshoot below. (0x803fa067) “
Causes of Error: This error mostly happens when upgrading from Windows 10 Home to Windows 10 Pro. The primary cause of this error is systems files being altered during previously installed Windows updates, or Windows update is disabled in settings, hence, users are not able to upgrade their Windows. You can read more about this error in this article.
How to Fix:
- First, check that your Windows is able to download and install updates by running a full Windows update.
- Restart your computer, disconnect the Internet connection, and then try the activation again.
If the error continues and you have verified that none of the two scenarios above is applicable to your case, then please contact our support team (info@primetechmart.com) for a quick help.
5. ENDING UP WITH WINDOWS 10 ENTERPRISE INSTEAD OF WINDOWS 10 PRO (0xc004c003)

Error Message: Sometimes this could come with the error message: “We can’t activate Windows on this device because you don’t have a valid digital license or product key. If you think you do have a valid license or key, select Troubleshoot below. (0xc004c003)” Sometimes it won’t have any error message, but you ended up with Windows 10 Enterprise instead of Windows 10 Pro.
Causes of Error: This error mostly happens when upgrading from Windows 10 Home to Windows 10 Pro. The primary cause of this error is that Windows is yet to fully download and installed all packages required for Windows 10 Pro. This could be due to mere glitch in the Internet connection or some system process which affected the download and/or upgrade process.
How to Fix:
- First, check that you have an active Internet connection.
- Then restart your computer and allow t to fully perform the upgrade process without interruption.
- Restart your computer again.
- Run a full Windows update and allow all updates to be fully installed.
If the error continues, please contact our support team (info@primetechmart.com) for a quick help.
6. ERROR WHEN MAKING A NEW WINDOWS 10 INSTALLATION

OR

Error Message: “The product key didn’t work. Please check it and try again, or try a different key.”
Causes of Error: This error happens when trying to make a new installation of Windows 10 either from a Windows 7 or 8 computer or when making a new Windows 10 installation on a blank disk using a USB installation media or DVD.
How to Fix: The simple fix for this error is to go back a step and select ” I don’t have a product key” as shown below.

OR

The proceed with the installation process normally. After the installation, simply go to ‘Control Panel → Under View by, select Large icons → System → Activate Windows or Change Product Key. Then enter the 25-digit product key you received in your email and proceed with the activation.

7. IF ALL FIXES FAIL
If the error continues after trying the above suggestions, please contact our support team via email (info@primetechmart.com) for quick help. For faster service, please include a screenshot of the error message you received as an attachment.
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