I had a legitimate copy of Windows 8.1 Pro installed on my laptop, I finally gave in to the annoying "upgrade to Windows 10" prompt.
Now I'm running Windows 10, but there is a message in the bottom right corner of the screen saying "Activate Windows". In the activation window of the settings application I get this: "Activation failed
because this device doesn't have a valid digital entitlement or product key" Error code: 0x803F7001".
I have googled this error, but solutions have not helped. I don't have a product key, as the computer came with Win 8. I haven't made any hardware changes.