How to Fix Activation Error 0xc03f6506 in Windows 10

In general, Windows 10 PC comes pre-loaded with the Home Edition. However, as this lacks several key features that Microsoft provides, users prefer upgrading their operating systems to Professional edition. To carry out all such conversions, you must have a valid digital license or genuine product key. In case you don’t, Windows 10 stays deactivated on an error message – “(0xc03f6506): The last product key you entered can’t be used on this copy of Windows“.

If you own an original product key, there are certain ways applying which you can get rid of this persisting error. In case of not having a valid license, you must purchase the same by visiting Microsoft’s official site. The same bug may also appear under the message –

Unable to upgrade your edition, We can’t upgrade your edition of Windows. Try upgrading your edition of Windows again. (0xc03f6506).

Imp: Receiving this error on Windows 10 doesn’t imply that you are using an invalid product key. It just means that you can’t use the same key to activate both Home as well as Professional Editions.

Windows Activation Error 0xc03f6506 Solutions

To solve the activation issue 0xc03f6506 on Windows 10 PC, try out the following fixes –

1. Modify the registry 

Modifying Windows Registry entries sometimes can help to fix this issue. If you had upgraded your operating system from Home Edition to Pro one, this is definitely a worth-trying procedure. All you need is to tweak two entries i.e. EditionID and ProductName under the CurrentVersion folder. Let’s check how to perform the needful changes –

  • Use Win + R keys combination to start the Run dialog.
  • Type “regedit” in the text field and press Enter to invoke the Registry Editor.
  • Navigate to the below directory or copy/paste the following path in the address bar –

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion

  • Jump to the right-hand side, locate and double-click the EditionID key. Type “Professional” inside the value data field and click OK.

Activation Error 0xc03f6506 - Modify Registry

  • Similarly, open the “ProductName” entry and change its name to Windows 10 Professional.
  • Next, go to the following directory –

HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows NT\CurrentVersion

  • Change the EditionID and ProductName values here as well (exactly the way you did before).

Activation Error 0xc03f6506 - EditionID and ProductName

  • When you are done modifying both these keys, close the registry, and Restart Windows.  

The activation error 0xc03f6506 shouldn’t appear thereafter. If it does, you may try the next set of solutions.

2. Activate Windows via Command Prompt

If you do have a bootable Windows media (containing a genuine product key), use that to activate your Windows copy. Here are the essential steps to work upon –

  • Insert the bootable Media at its respective port and Reboot your PC.
  • When Windows 10 reloads, launch Command Prompt as an Administrator
  • Type the initial letter of the volume containing the bootable media like D: or E: and press the Enter key.
  • Next, copy/paste the below command followed by the Enter Key again.

setup.exe /auto upgrade /pkey <25-characters Product Key>

Note: If your product key is not working, you may use the generic key by Microsoft. However, you still need to activate your Windows as this generic key helps only to upgrade your Windows Edition i.e. from Home to Pro. 

3. Disable Network Adapter

At times, being connected to a network prohibits switching to a different Windows 10 edition. So, we suggest disabling the network adapter first thereupon try to upgrade the Windows 10 edition again. Here’s how to proceed –

  • Open the Settings by pressing Windows Key + I.
  • Select Network & Internet > Change adapter options.

Activation Error 0xc03f6506 - Adapter Options

  • The system will then take you to the Control Panel. Right-click on the network from which you are accessing the internet, and choose to Disable.
  • You may now use the second method again to upgrade to Windows 10 Professional. 
  • If this works, Reboot your PC to incorporate the recent changes.
  • Sign-back into your device and re-enable the network that you have previously stopped.

Windows 10 OS still requires activation. Use either your purchased genuine product key or a digital license linked to your official account to activate this copy of yours. If you don’t have any of these, go to the Microsoft Store and purchase a genuine product key.