In order to hard reset a Nokia 7250i, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Nokia 7250i device will be brought back to the default configuration of a brand new device.
1. Push'n'hold the Power button until the phone turns on.
2. Press the Call button to bring up the phone's dialer and type in this code: *#7370#
3. Press the Call button again to confirm the process.
4. Done.