It's possible to prevent Windows 10 from installing automatically on your computer by using a simple free tool called GWX Control Panel.
After Microsoft made Windows 10 a 'Recommended' rather than 'Optional' update, plenty of users were surprised to find the operating system upgrade was due to happen automatically on their computer.
To prevent Windows 10 from installing, you need to delete its download and installation files, plus prevent Windows from installing them again. GWX Control Panel can do all of this for you.
If you are already upgraded to Windows 10 and wish to revert back to your older operating system, this is easy to do, so long as you act within 30 days. See our guide on rolling back from Windows 10.
Block Windows 10 with GWX Control Panel