Hard Reset SAMSUNG I9000 Galaxy S

First method:

1. Switch off your cell phone.
   
2. Press and hold Volume Up + Home button.
   
3. Keep pressing these 2 buttons + press Power button for 2-3 secods.
   
4. Release only Power button, but keep pressing  Volume Up + Home button until you see menu of Recovery Mode.
   
5. Then from this menu choose option "wipe data/factory reset" using Volume buttons to browse options, and Power button to confirm.
   
6. Now accept "Yes -- delete all user data".
   
7. Afterwards select "reboot system now".
   
8. Success!

Second method:

1. Make sure, that your phone is on.
2. Go into Menu -> Settings -> Privacy -> Factory Data Reset
3. Select Reset Phone.
4. Done!

Third method:

1. Turn on phone.
   
2. Press *2767*3855# on dialpad.
3. Turn off and turn on phone.

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