Q: Apple TV 2 home sharing quits

This happened to me for months. What solved it for me:

1. Upgraded my wireless to Airport Extreme Base Station from an older Netgear

2. Completely uninstalled Bonjour & iTunes, then downloaded & installed 64 bit iTunes (on Win7 64)

Not saying you have to run out and buy an AES, but try and see if uninstalling & reinstalling iTunes works.

Yesterday were released the IOS 5.1 and the Itunes 10.6. I thought that updating the IOS on the Apple TV 2 and the Itunes on PC, my problems would go away. I did that but for my surprise it has NOT.

Then I had a recall that I have read somewhere a while ago about issues with the AVAST Anti-Virus and Home Sharing, that can generate connectivity issues,

In one of my first temptatives to resolve this issue I have stopped the AVAST and I still had the problem, so I left this trail of solution. But since nothing was working I decided to uninstall it. I was a little skeptical about it but gave a shoot.

To my surprise, when I uninstalled it, booted the computer and did the Home Sharing, the problem was FIXED!

That made total sense because the other computer that runs Windows 7 and I have tested before, worked fine, it runs AVIRA as Anit-Virus software.

So my conclusion is that, on my case, the AVAST caused the issue and to stop its service was not enough to diagnose the issue. I had to uninstall it, believe or not. And that the issue has nothing to do with Windows Vista OS but with AVAST.

After that, I uninstall AVIRA  as Anti Virus software and, since that, the Library and Home Sharing (24 h ago) is working perfectly and I think that will stay.

I had the same problem.  I have Windows 7, 64 bit.  I did not completely uninsatll iTunes and Bonjour.  I went to "Add/Remove Programs" and located Bonjour.  I selected "repair", rather than "uninstall".  This worked for me.

Also verify that iTunes is allowed through your firewall "incoming connections".