How can I update my iPhone firmware / OS?
Your iPhone requires iOS firmware updates from Apple every once in a while to fix problems, add new features and plug security holes. To update the operating system on your iPhone to the latest release, follow these instructions:
1. Turn your iPhone on and connect it to your computer with the USB cable.
2. Launch iTunes.
3. Select the name of your iPhone in DEVICES on the left menu in the iTunes window.
4. Click the Check for Update button under Version on the main screen.
5. A dialog box will appear if a new firmware version is available asking if you wish to download the update and/or install.
6. To install the latest firmware click Download and Install.
7. Follow the dialog box instructions to complete the installation process on your iPhone.
iOS 5 and later can be updated over-the-air (OTA) directly on the iPhone, without a computer. For instructions on how to update iOS firmware OTA click here.