It can be useful to factory reset your Windows Phone 8 handset for various reasons. You might want to sell it, or you might have a problem with it which performing a reset might fix.
Whatever the reason, it's easy to do but not necessary something which is easy to find in the menu. Follow our step-by-step guide. See also: What's the best Nokia smartphone?
Note: A factory reset will delete all your apps and data stored on the phone such as contacts and photos. So make sure you backup anything you want to keep before you start. It's also helpful to have a decent amount of charge in the battery.
How to restore a Windows Phone 8 smartphone to factory settings
In the App list, find and click on Settings – shown by a cog.
See also: How to update a Windows Phone smartphone.
In the System section of the menu, click on About towards the bottom of the list.
At the bottom of this screen, click the box which says 'Reset your phone'.
You'll be presented with a warning message. Once you're happy to proceed, click 'Yes'.
Just in case, you'll get a second warning. Click 'Yes' when you're happy.
Your Windows Phone 8 smartphone will now reboot and be restored to its original factory settings.