A hard reset, also known as a factory reset or master reset, is the restoration of a device to the state it was in when it left the factory.
All settings, applications and data added by the user are removed.
The term is often heard in reference to smartphones and tablets but laptop and desktop computers, as well as most other electronic devices, can usually be restored to factory conditions.
1. First thing to do is turning your phone OFF, by holding down power button.
2. Now wait 10 seconds and press combination of power + home + volume down buttons at the same time.
3. Wait untill you will see LG logo, that's when you can release those buttons.
4. Then after few seconds your phone will boot recovery mode.
5. Use your volume buttons to navigate down to wipe data/factory reset option and select it with power button.
6. And now you know how to do hard reset on your LG Joy, good job!