0xC004C003, Activation server determined the product key is blocked

While trying to activate your Windows, you may see different types of Windows Activation Error Codes on your computer screen. Error 0xC004C003 is another activation error that has been reported by many users. This problem can mostly occur if the product key you are using will be invalid. With this error code, you may see the following message:

0xC004C003, The activation server determined the specified product key is blocked.

Sometimes a different error message can also appear:

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. Error code: 0xC004C003

The above activation error commonly occurs if you are using an invalid product key. You will have to buy a new product key. If you purchased a PC with Windows pre-installed, you would have to contact the PC manufacturer for the original key. If that does not help, read on.

Windows 10 Activation Error 0xC004C003

To fix Windows 10 Activation Error 0xC004C003, follow the below suggestions:

1. Run the Windows 10 Activation Troubleshooter
2. Make sure you have entered a valid Product key
3. Run Slmgr.vbs Command
4. Contact Microsoft Customer Support

Let us see them in details:

1] Run the Windows 10 Activation Troubleshooter

You may face Windows 10 Activation Error 0xC004C003 if the product key you entered is invalid. However, if it is not the case, you can solve this issue by running the Activation troubleshooter.

To do this, follow the below steps:

• Click on the Start button and select the gear icon (Settings) to launch the Settings app.
• Select the Update & Security category and then scroll to the Activation tab.
• Go to the right and click on the Troubleshoot link.
• In order to perform a repair strategy, click on the Apply this fix button.

If this method doesn’t solve the issue, go down to the next solution.

2] Make sure you have entered a valid Product key

If you’re trying to activate your Windows and receive an activation Error 0xC004C003 then it is possible that you have entered an invalid Product key. In such a case, use a different key and try to activate your Windows again.

3] Run Slmgr.vbs Command

The slmgr.vbs is a command-line licensing tool that you can use to configure licensing in Windows devices. It also helps to see the current licensing status of your Windows 10 installation.

To run the slmgr.vbs command, open the Command Prompt with the Admin right first.

Once it opens, type in the below commands and press enter:

slmgr.vbs /dlv

If it says GVLK, then the product was activated through Volume licensing and you are a part of it.

Next, run the below command to install the product key.

slmgr.vbs –ipk XXXXX-XXXXX–XXXXX–XXXXX–XXXXX

In the above command-line, replace the “X” letter with the Product key.

After that, again execute the below command in the same Command Prompt window to activate the copy of your Windows.

slmgr.vbs –ato

Once you are done, restart your device and see if the Activation Error 0xC004C003 still exists.

4] Contact Microsoft Customer Support

However, if none of the above-mentioned methods work and you are still encountering the Windows Activation Error 0xC004C003, then contact Microsoft Customer Support and ask them to activate your Windows. Microsoft support team will definitely help you to reset the product key for you.

All the best.