Fix Windows Activation Fails with Error 0xC004C003

A friend of mine wants to protect the data on his computer so I suggest using BitLocker to encrypt the whole hard drive. But his Windows 10 is only a Home edition that doesn’t have the business features such as BitLocker. Luckily, that didn’t stop him from using it. He took out the wallet and paid right there in the Activation window to upgrade his Windows 10 to Pro edition.

Things went well mostly until it’s failed, with an error code 0xC004C003.

Restart didn’t help. The troubleshoot button there did nothing either.

A quick Google search tells me that this is actually another Windows update that messed up the registry hive responsible for Windows Activation.

But the solution for either removing the update or installing a new one didn’t actually make the Windows activated.

What ended up working is the generic Windows 10 product key that reactivated the Windows.

In Setting’s Activation window, click the Change product key link and type in the following key to get your Windows reactivated.

VK7JG-NPHTM-C97JM-9MPGT-3V66T 

Note that, the key listed above is a generic Windows 10 key that will be used only to reactivate your Windows. Your copy of Windows will still be checked based on the keys embedded in the BIOS and your Microsoft Account used for purchasing the upgrade license.

Once done, also run the following command in an elevated Command Prompt window to make sure your Windows is permanently activated.

slmgr /xpr