Based on the identifier for your i Phone model, you can download the appropriate i OS firmware file or i OS software update for your i Phone from our download page.
The easiest way for most people to download i OS 10.3.2 is over-the-air, directly on their device. If you have limited space on your device or software update isn't working for whatever reason, you can update using i Tunes.
UPDATE : If you get a 1600 error while trying to restore to a custom firmware here, try this.
For complete specifications, images and reviews please check out the i Phone 4S product page.
What's New in i OS 9.3.5: i OS 9.3.5 provides an important security update for your i Phone or i Pad and is recommended for all users.
If your computer is using Personal Hotspot on the i OS device that you’re updating, connect your computer to a different Wi-Fi or Ethernet network before you update.
Additionally, you will also learn the best way to save your SHSH blobs which will allow you to downgrade your i Phone, i Pad, i Pod Touch and Apple TV firmware version in the future.
Below is a list of the direct links to the i Phone Firmware files for every released i Phone firmware version.