iTunes (12.1.2) won't recognise 5s

I just downloaded and updated my 5s to the iOS 9.1 via iTunes on my Windows 7 computer.

Once the update was complete and I restarted my phone to sync more music and app updates I got a message saying "...5s cannot be used because it requires a newer version of iTunes. Go to ..." Really annoying as I just got a CD I wanted to put on my 5s.

Can someone point me in the right direction on the site because I got to the iTunes downloading section and it instructed those who have iTunes installed on how to check for updates. I followed the instructions and my iTunes on the computer is the latest version.

Anyone shed some light on this issue?

I'd rather not have to delete and reinstall iTunes because that's inconvenient.

Many thanks in advance.