In order to hard reset a NEC N100, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
NEC N100 device will be brought back to the default configuration of a brand new device.
1. Hold down the Power button until a new menu will open.
2. After the phone turns on, press the Menu button.
3. Go to Settings Menu > Reset Settings. Enter the security code (default is 0000 or 000000 or 1234).
4. Lastly, confirm the whole process. Well done.