Troubleshoot Windows Activation Errors

If you see this error code, please contact us and mention that you are receiving error code 0xC004C008 in your message so we know what needs to be fixed.

This error code means the key does not match or is incompatible with the edition of Windows already installed.

For OEM keys:
You will see this error code if you are trying to upgrade from Home to Pro, or if you are trying to use a Home key on a Pro or higher installation.
(OEM keys do not support upgrades and should only be used during a fresh Windows installation by a system builder.)

For retail keys:
You will see this error code if you are trying to use a Home key on a Pro or higher installation. If you have an alternative edition installed, such as Home N or Pro N, a standard Home or Pro key will not activate these alternative editions.

Solutions:
The primary solution to this error code is to perform a fresh Windows installation (see guides below). Alternatively, you can use a different key that matches the edition already installed.

Installation guides:
Windows 10
Windows 11

Confirm that your device is up to date by checking Windows Update and installing any available updates

To check for updates, select Start  > Settings  > Windows Update > then select Check for updates.

If you’re unable to activate Windows, the Activation troubleshooter may help.

To use the troubleshooter, select Start  > Settings  > System  > Activation > then select Troubleshoot.

Make sure your computer is connected to the internet.

To check your network connection, select Start > Settings > Network & internet. The status of your network connection will appear at the top.

Restart your PC and try the activation again.

To restart your PC, select Start > Power > Restart.

You may be given the option to activate by phone.

To activate by phone, go to the Activate Windows Now section > then select Activate by Phone.