Samsung Galaxy S II Epic 4G Touch hard reset
Reset T989, reset Samsung i777
Press and hold Volume UP + HOME + POWER. Select factory reset with volume down. Press power to reset.

To reset your D710 device:
1. Press HOME > and Apps tap Settings > Privacy > Factory data reset. Read the Factory
Data Reset information.
2. To clear music, pictures, and other user data, add a checkmark to Format USB storage.
3. Read the disclaimer and tap Reset phone.
4. If you are certain that you would like to restore all factory settings, tap Erase everything.
or
Use this method to hard reset your Samsung Galaxy S II Epic 4G Touch: Enter *2767*3855#. Warning! All your data including contacts, messages etc. will be lost! Copy all your necessary data/Contacts/Messages etc. to SIM or make backup to your PC before full reset! Take out SIM card before full reset.