How do I upgrade from Windows 8 to Windows 8.1. I want to reserve to upgrade to Windows 10.? How do I upgrade from Windows 8 to Windows 8.1. Is this a free upgrade? I want to reserve to upgrade to Windows 10.? Yes, Windows 8 to 8.1 is a free upgrade. Make sure you have a legal copy and have the most recent updates installed. Go to the Windows store and there should be a big green tab that says something like Upgrade to Windows 8.1. It will guide you through the steps. ---- You have to have 8.1 to get the free upgrade to 10. You can upgrade from 8 to 8.1 from the Store App. it is free. ---