Four Easy Ways to Fix Windows 10 Activation Error 0xC004C003

The error code 0xC004C003 is basically an activation error and it occurs when you are not using a genuine product key. And this appears when you are still trying to activate Windows 10 using a duplicate or already-in-use key. This is not a new bug and hence you may resolve this by simply applying the fixes mentioned in the below sections. However, let’s first learn what may cause this error code in Windows. 

What may cause an activation error 0xC004C003 in Windows?

This activation error usually appears after replacing major hardware, using an invalid product key, etc. In certain cases, users simply install an advanced Windows 10 Edition like Pro, Education, or Enterprise instead of Home. Doing this also results in activation error 0xC004C003.

If that’s the case, simply clean install the Windows 10 Home version and this error resolves on its own. The Activation error 0xC004C003 may also occur due to some other reasons and they are as follows –

Windows 10 Activation Error 0xC004C003 Solutions

To solve the 0xC004C003 error on Windows 10 PC, try the following suggestions –

1] Run Slmgr.vbs Command

Windows 10 is widely used all over the world owing to its great GUI and simplicity, there is a possibility of activation servers being overloaded. In certain situations, the server simply rejects several new connections. So, we suggest to for a few hours and re-attempt. If the error persists, follow the below guideline –

Quick Note: This method works only if you were using a legal copy of Windows 10 previously. 

  • Launch Command Prompt first having administrative rights.
  • On the elevated console, copy/paste the below command and hit Enter.

slmgr.vbs –rearm

  • When this code runs successfully, Restart Windows to incorporate the above changes. 


Sign back in and check if this activates Windows 10 devices or not. 

2] Sign in to Microsoft Account containing Digital License 

In general, when we fresh install Windows 10, the system prompts us to sign into a valid Microsoft Account. Doing so will register the hardware and create a digital license for future reference. This DL is linked to your account and you may use this in the event of re-installing Windows. So, you don’t require to re-enter the product key as the Activation gets completed via the Digital Entitlement method. 

However, this starts to fail if you have replaced any major component on the computer like – Motherboard, hard disk, etc. In such scenarios, get in touch with Microsoft Customer support and let them know of any recent hardware changes. 

3] Perform an In-Place Upgrade

Performing an In-place upgrade often resolves hardware issues thus fixing the 0xC004C003 error. Don’t make high hope as there is a slight possibility that you may get back the above activation issue again. However, this indeed fixes any other bugs persisting on the computer. 

Note: Make sure to check the “Keep my files, settings, and applications” box while re-installing Windows 10. 

4] Recheck the Product Key

If you haven’t used a Microsoft account previously to sign in to your computer, you simply don’t have any digital license linked to your account. In such cases, you need to manually enter a genuine product key and attempt to re-verify this. The key should work if not used to activate Windows elsewhere. Otherwise, sign in to the official website and buy a new product key.

That’s it, I hope this guide helps to fix the Windows 10 Activation error 0xC004C003.

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Soni Aryan

Soni Aryan

Soni Kumari is a tech enthusiast known for her expertise in how-to type topics and Windows troubleshooting articles. She loves exploring how to do things or tweaks in Android, iPhone, and other operating systems.