How to fix the Windows 10 activation error 0xc03f6506

Many home users tend to get a computer with Windows 10 Home. Since Windows 10 Professional offers even more features and utilities than Windows 10 Home, many people choose to upgrade from Windows 10 Home to Windows 10 Professional. However, in doing so, some people may encounter the 0xc03f6506 error.

The 0xc03f6506 error appears when you try to upgrade Windows 10 Professional from Windows 10 Home. To upgrade to Windows 10 Professional, you must enter a valid license key, which will upgrade your system to Windows 10 Professional after a reboot.

However, sometimes Windows does not accept the license key you are trying to enter and gives an error code like 0xc03f6506. This can be caused by various reasons, such as the fact that the key has already been used on another computer, your network connection, etc.

This error 0xc03f6506 usually occurs when you want to activate Windows 10

The last product key you entered cannot be used for this copy of Windows (0xc03f6506).

However, it can also happen during the upgrade process itself.

Unable to update your version, we cannot update your version of Windows. Try updating your version of Windows again. (0xc03f6506).

Today, we will see how to overcome this error in both scenarios and upgrade your respective computer to Windows 10.

What is the cause of Windows 10 activation error 0xc03f6506

What is the cause of Windows 10 activation error 0xc03f6506

The factors behind this error code may vary, but they are usually due to the following reasons.

Fix Windows 10 activation error 0xc03f6506

Fix Windows 10 activation error 0xc03f6506


  1. You can also try activating Windows 10 while disconnected from the network. Open “Launch” access.
  2. Type Ncpa.CPL in the Open box in Run.
  3. Click OK to open the registration window below.
  4. Right-click on your network connection and select Disconnect.
  5. After that, try activating Windows 10 again with the key.

Activating Windows 10 via the command line

  1. For this method, you will need bootable Windows 10 disc media. In this case, insert the Windows 10 bootable media into your laptop or desktop.
  2. Type cmd in Run. Then press Ctrl + Shift + Ener to open the command prompt as administrator.
  3. In the command prompt window, type the letter of your boot drive, such as D: and press Return.
  4. Then enter this command:
    setup.exe /auto upgrade /pkey xxxxx-xxxx-xxxx-xxxx-xxxx-xxxx.
    Replace the xxxxxxx – xxxxxx – xxxx – xxxxxx – xxxxxx with your actual product key.
  5. Press the Return key on your keyboard to execute this command.

Changing the registry

  1. Right-click on the Windows 10 Start button and select Run to open this utility.
  2. Type Regedit in the Open field and click OK to launch the registry editor.
  3. Navigate to the next registry location:
  4. Computer -> HKEY_LOCAL_MACHINE -> SOFTWARE -> Microsoft -> Windows NT -> CurrentVersion.
  5. Double-click the “EditionID” line to open the window that appears just below.
  6. Delete the current Core value (Windows 10 Home). Then enter Windows 10 Pro in the Value data field to replace it.
  7. Click the OK option.
  8. Double-click the ProductName line.
  9. In the Value data field, delete Windows 10 Home. Enter Windows 10 Pro as a replacement.
  10. Click OK to close the window.
  11. Next, open this registry key:
  12. HKEY_LOCAL_MACHINESOFTWAREWOW6432NodeMicrosoftWindows NTCurrentVersion.
  13. There, change the values of the EditionID and ProductName lines just like you did in steps five and eight.
  14. Then close the registry editor window.
  15. Restart Windows after editing the registry.

Frequently Asked Questions

Select Start -> Settings -> Update and Security -> Activation, then select Troubleshooter to start Troubleshooting. For more information about troubleshooting, see Using the Troubleshooter.

  1. Open the Settings app.
  2. Go to Updates and Security -> Activation.
  3. If your copy of Windows is not activated properly, you'll see a Troubleshoot button. Click it.
  4. The troubleshooter will now scan your computer for possible problems.

If your genuine, activated Windows 10 suddenly stops activating, don't panic. Just ignore the activation message. Once the Microsoft activation servers are available again, the error message will disappear and your copy of Windows 10 will be activated automatically.

Open the Windows Registry Editor by pressing Windows + R, typing Regedit, and hitting Enter. In the right window, double-click the "PaintDesktopVersion" value. Change the value of "1" to "0" and click OK to save your changes. Close the registry editor and all other programs and restart the computer.