Step 1: First turn off your Samsung smartphone.
Step 2: Release any SIM card and SD card on your smartphone.
Step 3: Press and Hold Vol+ key, Home key and Power key 10 seconds.
Step 4: After some time you got system recovery mode Use Vol – key select wipe data/factory reset and press Power key to confirm.
Read also: How to Hard Reset Samsung Galaxy S2 4G I9100M with Factory Reset
Step 5: Use Vol- key to select Yes — delete all user data and press Power key to Confirm. (Notice: when you select Yes — delete all user data and press POWER key you lost your phone all user data)
Step 6: Wait until complete reset your phone, select reboot system now and press Power key.
Step 7: Now your smartphone will reboot.
Step 8: Your Android smartphone is now OK!!
