Troubleshooting Your iPad: Restore
Restore is a troubleshooting step of last resort for your iPad. Before you give up on your poor, sick iPad, you can try one more thing. First, connect your iPad to your computer as though you were about to sync. But when the iPad appears in the iTunes sidebar, click the Restore button on the Summary tab. This action erases all your data and media and resets all your settings.
If your computer isn’t available, you can also trigger this step from your iPad by tapping Settings→General→Reset →Erase All Content and Settings.
Because all your data and media still exist on your computer (except for photos you’ve taken, contacts, calendar events, notes, and On-the-Go playlists you’ve created or modified since your last sync), you shouldn’t lose anything by restoring except possibly e-mail or text messages sent or received since your last backup.
Your next sync will take longer than usual, and you may have to reset settings you’ve changed since you got your iPad. But other than those inconveniences, restoring shouldn’t cause you any additional trouble.
Performing a restore deletes everything on your iPad — all your data, media, and settings. You should be able to put things back the way they were with your next sync. That said, you may still be able to restore from an iTunes or iCloud backup.