Airplay icon missing in iTunes

So what else is new?

I've done it all... updated iTunes, confirmed home sharing, powered on the receiver, verified the same WiFi network, rebooted the computer, restarted iTunes, but still no Airplay button. This time, when I first started iTunes the Airplay button was there. I opened it, saw my receiver listed, clicked on it, the progress circle spun a couple times and then the Airplay button disappeared in its entirety.

I've researched this topic endlessly and I've tried countless times to make it reappear with no luck.

My goal: play music from my iTunes catalog using my Windows 7 computer on my H-K AVR 1700 receiver. Is that too much to ask?