Was your Windows 10 Pro activation registered with your Microsoft Account?
https://support.microsoft.com/en-us/windows/activation/activate-windows
Search results for, 0xC004C003
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I purchased a Windows 10 Pro retail key in 2020 and Windows was activated for years. After replacing my motherboard, Windows activation failed. The current error is 0xC004C003: "The activation server determined the specified product key is blocked." My Microsoft account still shows the device. Please check whether the license can be reactivated or recovered.
Was your Windows 10 Pro activation registered with your Microsoft Account?
https://support.microsoft.com/en-us/windows/activation/activate-windows
Search results for, 0xC004C003
The error code 0xC004C003 indicates the activation server has found a problem with the product key you are trying to activate Windows with.
1
Open the Settings App.
Go to System - Activation.
Click the Troubleshoot button and choose 'I changed my hardware', is that process successful, if not, what error is indicated.
2
Download the free ShowKeyPlus app from the Microsoft Store.
On the left of that app, click 'Check Edition', then enter your product key into that app.
Please provide a screenshot of that app window and please hide your product key in the screenshot.