How to Fix Windows Activation Error 0xC004F050

Error 0xC004F050 displays the description: "The Software Licensing Service reported that the product key is invalid."

Common Causes of Error 0xC004F050

• Edition Mismatch: Attempting to use a Windows 11 Pro key on an already installed Windows 11 Home edition without performing the offline upgrade step.
• Typo in Key Entry: Mistaking characters (such as 8 for B, or 0 for O).
• Stale License Cache: Corrupted tokens in the Windows Software Protection Service.

Solution 1: Reset License Tokens via slmgr

1. Open Command Prompt as Administrator.
2. Type slmgr /upk and press Enter (this uninstalls the current inactive key).
3. Type slmgr /cpky and press Enter (clears the registry cache).
4. Type slmgr /ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX (replace with your WindowsKey key) and press Enter.
5. Type slmgr /ato to trigger online activation.

Your Windows installation will activate immediately.