For most users, upgrading to iOS 7 has been smooth and hassle-free. But a lot many of us do face errors and hurdles when we upgrade to iOS 7 from whatever version of iOS 6. There are many reasons for the errors and we'll try to sort them out so you can upgrade to iOS 7 successfully.
Before you begin going through the various fixes mentioned here, you must remember that you need to have the latest version of iTunes in order to successfully upgrade to iOS 7. This is a mandatory step if you don't want to end up in any trouble when upgrading. At the time of this writing, iTunes's latest version is 11.1 and can be downloaded from here.
Check the Hardware First (Error 4013)
One of our cables wasn't working fine but we never knew this at the time of upgrade. iTunes kept throwing some or the other error every time – most prominent of it being the Error 4013. It would be best to check your cables and ports before you try anything software-related. This means:
- Use new or alternate cables when you connect the iPhone/iPad to the computer
- If you keep hitting errors, try different USB ports
Fixing Memory Issues
Not enough memory on the iPhone is usually a problem when it comes to an OTA installation of iOS 7. However, the same can also result in errors when iTunes tries to install iOS 7 on your iPhone. Low memory issues can be a problem hard to fix because you get unknown errors although they're rare.
Fixing this, however, is easy. Before you upgrade, make sure your iPhone has enough memory (at least, a few GB free).
The Hosts File, Clearing DNS Cache etc.
In a previous troubleshooting mode, did you ever encounter and fix Error 3194? If so, chances are high that you configured a “hosts” file. This results in a “hosts” block which can be pretty hard on an iOS 7 upgrade process. It won't let you upgrade at all till it's fixed.
There is a simple way to fix this: changing the hosts file, reverting it back to its original status.
To do this on Windows:
- Navigate to C:/Windows/System32/drivers/etc/hosts
- Backup the file to desktop and open the original file
- Try to find a line that has gs.apple.com
- If you find a line that has the URL, remove that one and save the hosts file.
To do this on a Mac:
- Navigate to /private/etc/hosts
- Repeat the same process as above.
If you don't find a line like that, you can try using TinyUmbrella.
Clearing DNS Cache
Clearing out the DNS cache after the steps above is also an addition thing to try. So whenever you clear out the gs.apple.com references in the hosts file, you should also clear out DNS cache just to be sure.
On a Mac, open the Terminal and type: dscacheutil -flushcache
On Windows, open the command prompt and type: ipconfig /flushdns
And then try upgrading to iOS 7. With luck, you should be able to do it successfully.