1. Switch off the device.
2. Then Press and hold the Home/Menu key + Power key simultaneously for 10 seconds.
3. Your phone will reboot with an Android logo appear, you sould be in Android System Recovery Mode.
4. Now press the Volume key to select the Wipe data/factory reset option.
5. Press the Menu/Home key to select and confirm your choice.
6. Now wait for your device to reset it self.
Your Samsung Galaxy Mini device now should back to factory setting. All previous settings are now back to default and you can start over again.
1. Press Menu.
2. Select Settings.
3. Select Privacy.
4. Select Factory data reset.
5. Now tap on Reset Phone.
6. Now tap Erase Everything.
Your Android OS will start to reboot and start up again.