1. Press Power Key To Turn On Your Device
2. Now Press and Hold * key + 3 key + Call button + Power button.
3. when show logo on screen release all keys.
than enter your security code.
Nokia mobile default security code is 12345.
2nd method :
First Backup Your All Data and make sure your mobile battery is not empty
Type This Code use keypad *#7370# or *#7780#
Now Press call button to confirm hard request.
3rd method :
Turn On Your Device First Press Menu Settings -> Phone -> Phone management -> Factory Settings -> Delete data and restore.
now press "yes" to confirm hard reset.
after few second hard reset finish
done.
