The increasingly creaky, bloated mess that is iTunes strikes again with the 12.3 release, which appears to have broken the ability to backup and sync older iPhone, iPad and iPod Touch devices.
While many users now backup their devices strictly to iCloud, Apple's 5 GB free offering is often insufficient to complete a backup. The security conscious also feel more comfortable having a backup locally stored and encrypted on their computers via iTunes. Using iTunes rather than iCloud also markedly improves the speed at which restores happen when switching to a new device.
It's ironic and bad timing that this flaw is occurring just as the iPhone 6S devices are being released, and many users want to therefore do just that - backup and restore their old 5 or 5S to their shiny new 6S. Well done, Apple.
It appears this issue is primarily occurring in iTunes on Windows 10, but others have reported it on Windows 7 and 8 as well, but only with the current released version of iTunes 12.3. There are many discussions about this in Apple's forums, but Apple doesn't seem to have acknowledged it formally, or offer much of a fix.
Here's how to solve the problem:
1. Close iTunes 2. Search for "Device Manager" and open it (you will need to be an Administrator or allow the prompt) 3. Find "Portable Devices" in the list, and expand to reveal Apple iPhone 4. Click on Properties, then the Driver Tab and click Update Driver 5. Choose the "Browse.." option then click on the Browse button and click through to C:\Program Files\Common Files\Apple\Mobile Device Support\Drivers 6. Click Next and Windows should install the correct driver. 7. Close the Driver Update window and Device Manager 8. Restart iTunes and reconnect your device, which should now show up in the top left corner as normal