With the phone turned off, press and hold
VOLUME DOWN + UP + HOME BUTTONS + POWER ON Galaxy Apollo GT-i5801
1- Turn the phone off.
2- Hold volume UP and down and menu(central button) while turning on the phone.
3- In Android system recovery select "Wipe data/factory reset".
4- reboot your system.
Use this method to hard reset your Samsung I5801 Galaxy Apollo Android phone: 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.