First method:

1. Begin by switching on the device by using the Power key.
2. From the Home Screen go to Menu and then to Settings.
3. Tap Reset and then select Master Reset.
4. In the next step choose Yes to confirm the whole operation..
5. To begin hard reset process type in the following safety code: 1234.
6. That's all.

Seconds method:

1. At the very beginning hold down the Power button to switch on the device
2. In the next step tap the following code in your phone: *2767*3855#
3. You should see information about resetting your phone.
4. Wait to comple the whole process.
5. Well done! Tha hard reset has just been performed.