→Torn Off Your Mobile.
→Remove SD Card, Sim Card and Battery From Your Mobile.
→Insert The Battery In Your Mobile.
→Press And Hold Power Key + Volume Down Key + Home Key.
→When Come Samsung Logo, Release All Keys.
→Select wipe data/factory reset.(Using Volume Key)
→Press Power Key.
→Select yes----delete all user data. (Your all Data Deleted) Press Power Key.→Wait Few Seconds.
→Select reboot system now.
→Press Home Key.
Your Mobile Rebooted and OK