Samsug Galaxy S4 Hard Reset

force reset Reset the device: Press and hold for more than 7 seconds to reset the device if it has fatal errors or hang-ups, or freezes.

sgs4 hard reset  or reset Galaxy S4: PRESS AND HOLD VOLUME UP + Home Button + Power. Keep holding HOME + Volume UP, but after vibrate release power.

Unlock Galaxy S4 using hard reset

Turn the phone off.
Press and hold VOLUME UP and Home (middle) button
Press Power until the phone vibrate
Wait until you see the Android logo then release all the buttons.
Select Wipe data/Factory reset with VOLUME DOWN, press Power (right hand-side)
Select YES -- delete all user data with VOLUME DOWN and then press Power
After format, press Power again to reboot phone. (select reboot system now)