Before we start with this tutorial, please note that doing hard reset or factory reset will completely remove all of your data on your phone, including apps and all your settings. You’r Lumia 521 then will have a clean install just like in the first time you turn in on.
There are two ways to do hard reset on Nokia Lumia 521. First from the phone setting menu and the other one is by using hardware button on your lumia 521.
Using Phone Setting
- Unlock your phone then go to Setting menu
- Scroll down and find About menu.
- Press Reset your phone, then confirm it by pressing yes
Using Camera + Volume + Power Button
- Press and hold the Camera + Volume Down + Power button simultaneously
- Release the Power Button when your phone vibrate but keep the other button hold
- When format prompt show up on your phone screen, release the camera and volume button
- Press windows button twice to confirm
Please not that this action can not be undone, so be careful and make sure to backup your data before you do this factory reset.