Make sure you are running the public release of Windows 10 (version 10.0.10240 or better).
You can find your current build number by clicking the start button, typing "winver", and hitting the Enter key.
If you're not running Windows 10 (version 10.0.10240 or better) you can upgrade from here.
Your session has expired. Please sign-in again to continue. Unfortunately any unsaved changes will be lost.