Before you try to update you should check your device is supported by the operating system. Supported devices are the : iPhone 3GS, iPhone 4, iPad, iPad 2 , iPod Touch 3G and 4G.
Once you've established your device is supported you need to install the latest version of iTunes on your Mac or PC. After you've done that connect your Apple device to your computer using USB and open iTunes.
Before doing the update to iOS 5 we suggest you backup your data in case anything goes wrong. To backup your data open iTunes select your device and click sync.
iTunes should automatically prompt you to install iOS 5 , but if it doesn't you can manually check for updates by clicking "check for update" in the summary screen for your device. You can then follow the on-screen prompts to download and then install the latest updates to your Apple device.
If you encounter any loss of data you can recover it by re-syncing with iTunes and then selecting recover purchased content.
