Itunes not recognising any of my devices?

I plugged in my iPod nano 7th generation the other day to sync a new album to it and a message popped up saying: 'An iPod has been detected, but it could not be identified properly. Please disconnect and reconnect the device.' The iPod worked fine the day before this happened so I have no idea as to the cause. I followed all of the steps on the apple website and forums and nothing worked. I then tried to put the songs on my iPhone 5S, which it was connected to over wifi, when the sync failed. I plugged the iPhone in and the exact same message popped up? I took it to the store and they said to replace the iPod, but its obviously not the iPod its my computer.

I've already tried fully uninstalling iTunes and reinstalling it and still nothing, i've updated drivers and deleted preferences, switched wires and ports and pretty much everything else on the web and I'm honestly clueless as to what the next step to try is!!

Since when did putting a new album on an iPod get so tricky?