As soon as Apple releases update to iOS for iPhone, iPad and iPod, Apple users update iOS on their devices to enjoy new features and innovation. The update process is simple for many but it also proves to be complicated for even more users. Many jailbreak their Apple device, and also there are requirements for iOS update if you provide iTunes a downloaded iOS file. If you download and update via iTunes, device still communicates to the Apple servers to verify the update. Error is likely to happen for many users. A common problem is observed where iTunes prepares iPad, iPhone or iPod for several hours. Endlessly you see this message displayed in iTunes.
Recently I updated to the latest iOS version on my iPad and I encountered this problem several times. This message is a hint that an error will most likely occur ahead. Normally when you provide a downloaded ipsw file to iTunes, it is extracted by iTunes and then iTunes prepares the device for it and then device updating starts right after that. You will be able to see the progress bar on iTunes and the device also displays the update progress.
If the device is in DFU mode or in recovery mode and the iTunes is displaying the same message “Preparing the device”, it means that something is wrong and you need to fulfill iOS update requirements. Something you need to check with the internet connection, computer hosts file, security software or anything else. Something is interrupting the communicating between Apple device and the Apple servers.
It might be the case that you have provided the incorrect iOS build for your device. If you are sure about the correct file, then read instruction in following articles:
If you see this state for more than five minutes, no need to wait more. Disconnect the device from computer, check and fix issues as described in the articles above, again connect the device to the computer and start the update process again.
Another thing to note is, you will encounter this issue while updating the Apple device via iTunes. If nothing works, you can always update iOS from the device without connecting it to computer and iTunes. Do update device ‘Over the Air’. You need to enable Wi-Fi from device and go to:
Settings > General > Software Update
Hit button there that says > Download and Install
The device will download the latest iOS from Apple servers and update your device and you won’t need to be worried about the ‘iTunes preparing the device for update’ issue.