Error code: 0xC004C003 for Windows Update

Forum people, I am in need of your assistance! I wanted to do a clean install of Windows 10, never guessing issues I might encounter. I skipped the key part, since I already activated my account while purchasing Win 7 version. Now, I get this error code when I was checking my activation:

  • "The activation server determined the specific product key has been blocked. (Error code: 0xC004C003)

Help would be really appreciated!

Hi @Bentley,

I think you are using a MAK key which has been blocked. These keys are set to activate only set number of computers, and cannot be reused, and hence only installed on computers which do not go through the installation process. The only solution is to contact the Microsoft Activation Call Center to obtain a new MAK and install/activate the system.

Hope this helps

Hi @Bentley

This error can occur if the activation servers are busy. If that’s the case, simply wait for a couple of hours and try to activate Windows 10 again.

Hello Sir,r
You can check the following steps given by Microsoft website

You may see this error because the Windows 10 product key you entered isn’t valid. Product keys are unique—assigned to a specific user to install on a single device. If a key was used (or attempted to be used) on multiple devices, it’s marked as not valid. To activate Windows, you’ll need to provide a different Windows key unique to your device.

If you bought a device from a reseller of Windows 10 and expected the key to be valid, contact the reseller. If your device was purchased with Windows 10 preinstalled and you received this activation error upon turning it on for the first time, contact your device manufacturer.

If your experience with your device is different from those listed above, try the following:

  • Run the Windows 10 Activation Troubleshooter: Select Start > Settings > Update & Security > Activation and then select Troubleshoot .
    Open Activation settings
  • Check to see if you have a paper copy of your Windows 25-character product key you can enter to activate Windows 10.
  • If your device was recently repaired at an independent repair facility, contact them to see if the repairs require a new Windows 10 license.
  • If the device is new and has never been activated, contact your device manufacturer.