In order to hard reset a Samsung i710, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Samsung i710 device will be brought back to the default configuration of a brand new device.
1. Switch off the phone.
2. Now press the Windows and OK buttons simultaneously (you might want to use your left hand's fingers for this).
3. Use the stylus to press the Reset button.
4. Release all the held buttons simultaneously.
5. Allow your phone to reset and restart, thus completing the hard reset process. Kudos.