Updating iphone from another computer
Your i Phone notifies you when an update is ready for you to install, but it’s easy to ignore that notification, or to dismiss it without realizing what you’re missing.
If you’re not sure whether your phone has an available update, look at the icon for the Settings app.
If i Tunes tells you that a more recent version of the application is available, download it.
Accept all prompts necessary to install the updated software.
If it has a red badge with the number one on it, then it’s probably time to update your software.
Apple offers two ways to update your i Phone: over the air, and via i Tunes on your computer.
The other i Phone updates that Apple releases each year are more minor, and often fix security issues and squash smaller bugs that have made their way into the programming code.
Fix: If you do not see the tray icon, you do not have Dropbox installed on your computer.
But if you have i OS 5 or higher, that's not true anymore.