To reset a Samsung Galaxy S2, access the "Privacy" menu and select "Factory Data Reset." This deletes all information and downloaded applications. There is also an alternative method, used if the standard reset fails, but as this is done by accessing the phone's boot menu, it may require direct support from your service provider to complete.Continue Reading
Before performing a master reset, store important data on an external device such as a SIM card, an SD card or a computer. A master reset returns the device to its original settings, so any personal data, ringtones, pictures, videos and applications are permanently deleted and unrecoverable.
At the home screen, select the Menu key and tap "Settings." Scroll down until you reach the "Privacy" option, and select it. Tap the "Factory Data Reset" option.
If you wish to delete all saved media and applications from an SD card as well, be sure to insert said card, and check the "Format USB Storage" box. Next, select the "Reset Phone" option at the bottom of the screen. Finally, tap "Erase Everything" on the next screen.
If you are having difficulty performing any of the required actions, call your service provider for support.