Nokia 7210 hard resetYou can format your device by typing *#7370# in standby mode. Before the device is reset, you need to provide the lock code. The default lock code is 12345.
Nokia 7210 phone can be reset via this menu option
Press menu button or enter Menu > Settings> Restore factory settings > Enter security code> 12345 YES
Formatting the device will permanently erase all user data and settings as well as add-on applications and operator specific settings.