How to update / restore your iPhone/iPad/iPod using the downloaded IPSW file:
1. Download the firmware to your hard drive
2. Connect your device to your Mac or PC using the connection cable
2. On Macs OPTION-click and on PCs SHIFT-click the Update / Restore button in iTunes
3. Select the IPSW file you downloaded to update / restore your device
4. Wait for the iPhone / iPad / iPod to finish the process
About iPhone / iPad / iPod Firmware:
iOS (iPhone/iPad/iPod Firmware) is a collection of firmware update files (IPSWs) for Apple's popular iPod and iPhone devices. The IPSW files provide a very quick method for updating the software on your iOS device via iTunes.
Install this firmware and your device can benefit from improved system stability, network-related functions and performance, enhanced touch experience, various fixes for problems encountered throughout the device’s usage time, as well as several other changes.
Bear in mind that, before you get this release, you must check to see if the available firmware is developed for your model and SKU (stock keeping unit) – if you apply an incompatible software, the device will encounter serious malfunctions and can even be rendered unusable.
Please make sure the you reboot your device after the update process is complete and check to see if you have the latest available iOS version.
It is highly recommended to always use the most recent driver version available.
Try to set a system restore point before installing a device driver. This will help if you installed an incorrect or mismatched driver.
Problems can arise when your hardware device is too old or not supported any longer.