Restoring iPhone Back to How You Bought It
To return your iPhone back to its original condition, all you need to do is restore your phone. This method for resetting iPhone clears all data from the phone and brings it back to how you bought it. So let's get to it. To restore your iPhone, follow these steps:
1) Connect your iPhone to your computer.
2) In iTunes, under the Devices, select your iPhone.
3) Select the 'Summary' tab across the top.
4) Click 'Restore'. (See screenshot below for steps 1-4)
5) After clicking 'Restore', you will be asked if you are sure that you want to restore your iPhone to factory settings (see example of the window pop-up below). Click 'Restore' if you are ready.
6) After confirming that you'd like to restore your iPhone, your iPhone is taken through several steps to restore it to factory settings. Notifications will pop up to let you know which phase of the process the phone is in. The phases occur in the following order: Extracting software, Verifying iPhone restore, Preparing iPhone for restore, Preparing iPhone for software restore, Restoring iPhone software, Verifying iPhone software, Verifying iPhone restore, Restoring iPhone firmware. These phases take several minutes to complete. Do not disconnect your phone while the phone is in the process of restoring.
7) The following notification appears to inform you that your iPhone has been restored to factory settings and is restarting. Click 'Ok'.
8) After you click 'Ok', your phone will restart. The Apple logo is displayed while it is starting up. When the phone comes back on, you may notice the iPhone says to connect to iTunes (see below for screenshot).
Ignore this screen, do not disconnect your iPhone. Wait until this screen goes away and changes to say "iPhone is activated" (see screenshot below).
Your iPhone is now restored to factory settings. You have no further steps to follow if you want your phone to stay free of data. If you want your phone restored from backup (to return all your saved data to your phone), follow the steps to restore your iPhone from backup on the next page.