User Guide

62 Chapter 4 Deploying iTunes
To update iPhone software, follow these steps:
1 On a computer that doesn’t have iTunes software updating turned off, use iTunes to
download the iPhone software update. To do so, select an attached device in iTunes,
click the Summary tab, and then click the “Check for Update” button.
2 After downloading, copy the updater file (.ipsw) found in the following location:
 On Mac OS X: ~/Library/iTunes/iPhone Software Updates/
 On Windows XP: bootdrive:\Documents and Settings\user\Application Data\
Apple Computer\iTunes\iPhone Software Updates\
3 Distribute the .ipsw file to your users, or place it on the network where they can
access it.
4 Tell your users to back up their device with iTunes before applying the update. During
manual updates, iTunes doesn’t automatically back up the device before installation.
To create a new backup, right-click (Windows) or Control-click (Mac) the device in the
iTunes sidebar. Then choose Back Up from the contextual menu that appears.
5 Your users install the update by connecting their device to iTunes, then selecting the
Summary tab for their device. Next, they hold down the Option (Mac) or Shift
(Windows) key and click the “Check for Update” button.
6 A file selector dialog appears. Users should select the .ipsw file and then click Open to
begin the update process.
Backing Up iPhone with iTunes
When iPhone or iPod touch is synced with iTunes, device settings are automatically
backed up to the computer. Applications purchased from the App Store are copied to
the iTunes Library.
Applications you’ve developed yourself, and distributed to your users with enterprise
distribution profiles, won’t be backed up or transferred to the user’s computer. But the
device backup will include any data files your application creates.
Device backups can be stored in encrypted format by selecting the Encrypt iPhone
Backup option in the device summary pane of iTunes. Files are encrypted using
AES256. The key is stored securely in the iPhone keychain.
Important: If the device being backed up has any encrypted profiles installed, iTunes
requires the user to enable backup encryption.