You may have noticed a new icon in your Windows System Tray that looks like the Windows 8 start menu icon. This magical icon lets you reserve your free copy of Windows 10 right now!
When you click on that icon, you’ll see the “How this free upgrade works” screen (shown above), with a button to “Reserve your free upgrade” in the lower left. Once you click the button, you’re done. You may optionally enter your email address to get a reminder to get a reminder about the update. Don’t worry if you change your mind; you can click on the icon in the system tray and cancel your upgrade.
You should also click on the hamburger menu in the upper left, and select “Your PC is ready”
You’ll see a screen that lists potential device or app comparability issues.
Hop over to C|NET to check out info on the updates, service packs, and patches you’ll need to have installed on Windows 7 and 8 machines before they can upgraded to Windows 10.