If you want a really simple and easy way to get rid of the “Get Windows 10” icon and stop your PC from downloading Windows 10, you can download a little piece of freeware called GWX Control Panel from a developer that isn’t happy with this nonsense either.
Download it, run it, and then click the “Disable Get Windows 10 App (permanently remove icon)” button. And then click the “Disable Operating System Upgrades in Windows Update” button too for good measure.
You’ll have to reboot, but at the end, the icon will be gone and your computer shouldn’t get the upgrade. And luckily you can click those buttons again to put things back the way they were.