Hard Reset SAMSUNG G800H Galaxy S5 mini

First method:

1. At the beginning switch off your device by holding the Power key for a short while.
2. In the next step press and hold together: Volume Up + Home + Power button for a couple of seconds.
3. You can release held keys when the Samsung Logo appears on the phone's screen.
4. Afterwards select "wipe data / factory reset" using Volume buttons to navigate and Power button to confirm.
5. Then choose "Yes -- delete all user data" to confirm the whole operation.
6. When the Recovery Mode menu appears again select option "reboot system now".
7. Well done! The hard reset has just been performed.

Second method:

1. If the display if off hold down the Power button to turn it back on.
2. From the Home Screen go to Menu and then to Settings.
3. In the net step tap Backup & Reset and then Factory Data Reset.
4. Afterwards find and select Reset phone.
5. To confirm your choice select Erase everything.
6. That's all. Wait to complete the operation.

WARNING !
Hard Reset will erase all of your data
All described operations you are doing at your own risk.