You can easily circumvent the issue by implementing a few solutions given below. Also, it is important to note that the error code doesn’t mean that your key is lost as long as it is valid. You will just have to activate your Windows using ‘not so generic’ methods.

What causes the Windows 10 Activation Error 0xc03f6506?

The factors that cause this error code can vary, however, usually, they are due to the following reasons — Now to get you back on the road, you can try the solutions given down below to isolate the issue.

Solution 1: Upgrade using the Command Prompt

If you are not able to use the license key to upgrade to Windows 10 Pro, you can try to do it using the Command Prompt. To do this, you will need a Windows bootable media. Once you have that, follow the steps given down below:

Solution 2: Using the Windows Registry

You can also try to tackle the issue by modifying a few entries in the Windows Registry. These modifications will help you to upgrade to Windows 10 Pro. We will change the entries of CurrentVersion and change the EditionID. Here’s how to do it:

Solution 3: Disabling Network Adapter

Finally, you can also try to use the license key by disabling your network adapter. In some cases, using license keys while disconnected from the internet can isolate many issues. Here’s how to do it:

How to Fix ‘An Error Occurred During Activation. Try Again’ Error during…[FIX] Windows Activation Error 0XC004F213 on Windows 10Fix: Windows Activation Error 0x55601 or 0x44578How to Fix Error 0xc004f014 During Activation on Windows 10 Fix  Windows 10 Activation Error 0xc03f6506 - 65Fix  Windows 10 Activation Error 0xc03f6506 - 98Fix  Windows 10 Activation Error 0xc03f6506 - 25Fix  Windows 10 Activation Error 0xc03f6506 - 60Fix  Windows 10 Activation Error 0xc03f6506 - 82Fix  Windows 10 Activation Error 0xc03f6506 - 57