In order to hard reset a Samsung Galaxy Ace Duos I589, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Samsung Galaxy Ace Duos I589 device will be brought back to the default configuration of a brand new device.
1. Turn on the phone.
2. Enter Apps menu. From there, go to Settings > Privacy > Factory data reset > Reset phone > Erase everything.
3. That is all, now you just need to wait for the phone to reset and restart. Whee.