Windows activation error code 0xC004B100 often occurs when trying to activate your version of Windows, perhaps after replacing your motherboard or processor. If you encounter error code 0xC004B100, read on. This guide explains possible workarounds for this Windows activation error that can help you solve the problem. So, let’s see how to fix this error code.

The error code is accompanied by an error message:

0xC004B100, the activation server has detected that the computer cannot be activated

Using the activation troubleshooter

If the problem is not caused by a violation of the restrictions imposed by your specific license, you can usually solve the problem automatically by running the activation troubleshooter.

This built-in tool includes a set of automatic recovery strategies designed to fix the problem in specific cases caused by situations such as reinstalling the operating system from a recovery environment or booting from a driver cloned for the first time in a different configuration.

Check your MAK key

The main reason may be that MAK is not supported. MAK or multiple activation keys are used to activate multiple devices. The number is pre-configured according to the agreement between Microsoft and Enterprise.

To resolve this issue, first make sure you are using the MAK key provided by Microsoft.

Activation by phone

Another possible cause of this problem is that you are changing your PC’s motherboard, but not following the instructions in the licensing process. In this case, successfully transfer the license using the phone activation method. The procedure is as follows:

  1. right-click Start and select Run.
  2. Type SLUI4 and press Enter.
  3. Select your country from the list provided and click on Activate Phone. List, then click Next.
  4. On the phone activation screen, call the number listed for your country.
  5. Correctly use the automated system as described.
  6. Write down the verification ID of the automated system.
  7. Now enter the validation ID specified in the field and click the Activate button.
  8. After completing these steps, check to see if this solves the problem.

Contact a Microsoft agent

If none of the above instructions apply to you and you are sure that your license key is genuine, all you need to do is contact a Microsoft Live agent and ask them to help you re-activate the license on your new motherboard.

You have several options to help you. However, the easiest way is to simply follow this link (here). Once there, click on the “Get Help” app to open it. Then all you have to do is wait for a live agent to talk to you so you can explain your current situation.

Most of the affected users who took this route reported that the Microsoft Live Agent was with them within minutes of starting the conversation. Note, however, that they will only help you as long as your license key is valid and you have NOT violated the terms of the software license agreement for your Windows license.