In order to hard reset a Nokia Asha 300, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Nokia Asha 300 device will be brought back to the default configuration of a brand new device.
1. Turn on the phone.
2. Press Call button to open the dialer. Type in this code: * + 3 + End Call
3. Let go of buttons held when Nokia logo appears on-screen. Press Call button to confirm.
4. Device will now reset and restart.