My version of iTunes will not recognize any of my AirPlay devices (Apple Tv and Airport). It once did, but several upgrades ago it stopped. Once in a rare while, it works, but for no apparent reason. I certainly can't duplicate it. I have tried starting and restarting, changing settings, ip stalling and reinstalling. It's been this way for months.
All of my Apple devices recognize the devices and can access the extended network. The Apple TV can retrieve pictures and works with my iPads and phone. Just not with the PC. Except every once in a while, of course.
I've checked the Norton and it appears that iTunes is Allowed under the firewall settings. And turning off the Firewall doesn't make it work.