Itunes doesn´t "home sharing" with Apple TV2 and Ipod. I does in the past with the same computer
I have lastest software of Itunes, Apple TV2 and Ipod Touch.
I already reset and re install software in Apple TV2 and Ipod.
I already check antivirus (kalpersky) and disabled Fire wall.
Also rest te WiFi router
A few months ago it works without a problem.
Apple TV (2nd generation), Windows 7