Updating an iphone
Here's how to perform the update using i Tunes on mac OS and Windows computers.
A warning appears if there isn't enough free storage space on the device to install the update.
Reset all settings – the settings on your i OS device will be restored to factory defaults, but apps and data won’t be deleted. As any other app, the App Store can be slow at times, or its functions may not work.
In this article we show how to download, install and run the latest version of i OS, as well as how to fix any problems that arise during the installation process.
(If these prove especially tricky, read What to do if you can't update i OS.) Note that i OS 12's days are numbered, in a sense; its successor, i OS 13, has already been announced, and will be released in September 2019.
You can also contact Apple or visit one of their stores.
These problems/solutions are found and effective on i Phone 4, i Phone 4s, i Phone 5, i Phone 5s, i Phone 5c, i Phone 6, i Phone 6 Plus, i Phone 6s, i Phone 6s Plus, i Phone SE, i Phone 7, i Phone 7 Plus, i Phone 8, i Phone 8 Plus, i Phone X, i Pad, i Pad Mini, i Pad Air and i Pad Pro.