It will remove all the data ,contacts and apps that you installed
Note: All data will be lost by this method take backup of important data before do that.
1.Power off your phone
2.Press and hold volume up + home button + power button
3.Release power button when Samsung logo appear
4.Choose with volume buttons "wipe data/factory reset" and select it with power button
5.Choose "yes delete all data " with volume buttons and select it with power button
7.Wait until the phone restarts
Samsung Galaxy S Advance I9070 Restore Factory Hard Reset Format Phone.So lets start the Samsung Galaxy S Advance I9070 Restore Factory, Samsung Galaxy S Advance I9070 Hard Reset.Turn Off the mobile phone for few mints.Samsung Galaxy S Advance I9070 Remove Pattern Lock.
Restore Hard reset will set your phone in origional factorry settings. It will remove all the data and apps that you installed. Your contacts will be removed and you have to add them again.