Learn how to perform a hard reset on the Samsung Galaxy S II device.
When you want to pass on your phone to some else it is a good idea that you wipe out all the data on your phone so that no one can get access to your personal data. You could also perform a reset if you device is frozen and not responding to your command.
Note: Performing the below actions will erase all your personal data, so if there is any data that you would like to keep please back them up first so that later you could restore them if you like.
If you are ready, then here's how:
1. Go to the Home screen.
2. Go to Settings.
3. Select Privacy.
4. Select Factory Data reset.
5. Select Reset Phone.
6. Select Erase Everything.
You devices should be resetting now.
Hardware Key Reset
1. Switch off the phone. Pull out the battery if you device is not responding.
2. Now press and hold down the volume up + volume down button. Then press and release the Home/Power button.
3. Next the phone will present a menu for you to choose, select Clear Storage.
4. Confirm if you want to go ahead.
Also you could try to key in *2767*3855# and press dial.