iTunes not showing the option to check for iOS Software Update

I have an iPhone 6 Plus 64GB with iOS 9.3.5 installed, Windows 7 (SP1) HP Laptop. The last few iOS updates (from about iOS 8 or 9, I have done 'over the air' rather than connecting to iTunes on my laptop.

This time, with iOS 10 being released and reading online about a number of iPhones being 'bricked' updating 'over the air', I decided to update by connecting via USB/Lightning cable to my laptop and iTunes.

When opening iTunes on the laptop, clicking on the device (iPhone) and 'Summary', it correctly showed the current software on my phone (iOS 9.3.5), but no option to 'check for updates'. It also says "Connect this iPhone using a USB cable in order to update or restore it's software", which seems strange, since it is connected via USB and is recognizing the iPhone's correct, current software version. After not being able to figure out why, I found also that iTunes 'check for update' said that v12.1.1 was current. After some searching online, I came across a website that showed iTunes was up to v12.4.3 at the time of writing. I therefore went to the Apple website to update iTunes, as I couldn't do it from within iTunes itself. I found that the latest version is 12.5.1.21 which I downloaded and installed (without uninstalling the previous version first). Still the same problem. I then uninstalled that latest, current version of iTunes on my laptop and reinstalled it. Still the same problem.

I have been able to 'Sync' and Backup the phone in iTunes without any issues.

Can anyone help please?

Message was edited by: colboy58 I was just considering taking a chance and updating the iphone software via the phone's 'Settings' App with the option of doing a 'restore' via iTunes on the laptop if I ran into problems. Then, though, I found that the "Restore Backup" button in iTunes was 'greyed out' and not 'clickable'.