Situation: You may see Windows Activation error code: C004C003 in your Windows 10 computer.
Troubleshooting: 1. In many cases, you may get this error code because the activation server is busy. You can wait for while.
2. Or just click Troubleshooting under Windows Activation.
3. If 1 or 2 don’t fix the problem and you are sure you have a valid license, you may try slmgr.vbs –rearm command to force Windows 10 to activate.
- Type cmd in the search bar. Right click on Command Prompt and select run as admin.
- In the command prompt type the command slmgr.vbs –rearm and pressing the Enter key. Wait for a couple of minutes and reboot your PC.
4. If you need to call the Microsoft support and don’t know the license key, you can get it by running a command.
- Type cmd in the search bar. Right click on Command Prompt and select run as admin.
- In the command prompt enter wmic path SoftwareLicensingService get OA3xOriginalProductKey command. It will show the Windows product key.
Please view this step by step video:
