As of Monday, Windows 10 is now a "recommended" upgrade for Windows 7 and 8.1 users. That means some computers may download the operating system automatically. Those who aren't sure they want to install Windows 10, or want to decide on their own time, may want to adjust their Windows Update settings.
It's important to remember that no matter what, users will be prompted to confirm whether to upgrade to Windows 10. After the upgrade, the operating system will also provide the option to revert to the old version within 31 days. However, downloading the update automatically will take up bandwidth and disk space, so there's plenty of reasons to cancel the Windows 10 update.
Windows 7 users will need to go to the Start Menu and search "update." The list of results should include "Windows Update." Open it up, then click "Change Settings." Uncheck the box that says "Give me recommended updates the same way I receive important updates," then click "OK."
For those on Windows 8.1, navigate to the "Settings" app by moving the mouse into the lower right corner and clicking the app when it appears. Then click "Change PC settings," then "Update and recovery," then uncheck the box that says "Give me recommended updates the same way I receive important updates," then click "Apply."
Note that Microsoft will eventually stop supporting Windows 7 and Windows 8.1. When that happens, PCs may become vulnerable to attacks and hacks from the outside world, so it might be better to simply upgrade now and relax. There's plenty of other reasons to upgrade, but those who want to avoid it for now can follow the above steps.