Be advised, they changed the Windows 10 update from "Optional" to "Recommended" which means that (depending on your update settings) now there's a one-hour timer displayed, and if you do nothing it will automatically update. So if you're away from your computer (like I was), you'll come back to find that you now run Windows 10. If you want to go back, you'll have to go into "Settings" > "Update & Security" > "Recovery" and select "Go back to Windows #" (# being the version you previously had). Then fill out a form on why you're going back. Then watch it like a hawk, because it will check for updates once you're back in your old version and will automatically start the update timer all over again. Once the timer's there, click on reschedule, and then find the option that says to cancel the update. Then make sure to cancel the Windows 10 download that already started automatically. Note that if it's been more than a month, you can't go back.
Here's a recent news article about it: http://www.express.co.uk/life-style/...-Automatically