Hard Reset SAMSUNG I9003 Galaxy S scl

First method:

1. Make sure, that your phone is off.
2. Then press and hold 3 buttons: Volume Up + Home button + Power button, and release onlyPower button when pass 5 second.
   
3. When you see menu with options, then release rest buttons.
4. Select option "wipe data/factory reset" using Volume Down to scroll, and Power button to accept options.
   
5. Now choose "yes" from menu.
   
6. After that accept option "reboot system now".
   

Second method:

1. Power off your phone.
   
2. Next tap this code: *2767*3855#
3. After that wait until your phone restarts.

Third method:

1. When your phone is on go to Menu -> Settings -> Privacy -> Factory data reset -> Reset phone -> Erase everything.

WARNING !
Hard Reset will erase all of your data
All described operations you are doing at your own risk.