Tried updating my iphone 4
If you are installing the update few months after the launch there should be no problems with busy servers or long delays.
In that case, if you are having issues with the download time, it may be that your Wi Fi network isn't performing.
If you're prompted to update your i Phone while you're using it, Apple now lets you choose 'Later,' which will then specify a time period during which it will update automatically for you if you've got your i Phone plugged in to a power source, which most people do overnight anyway.
When Apple prompted Macworld's own Ashleigh Macro to update to i OS 9.1 and offered that 'Later' option, she decided to make the most of the convenient new feature.
Once i OS 11 is downloaded on your device it will be verified by Apple.
If your device gets stuck on this screen it may be because your Wi Fi connection has dropped, so check your internet connection.
One solution is to delete lots of files from your i Phone and make room, then put them back afterwards.Or it might be that your i Phone isn't capable of running the software, in which case you won't see an alert at all. If you have an i Phone 5C, and i Phone 5 or anything older than that you will be out of luck! Find out more here: Can my i Pad or i Phone run i OS 11?