There is a process 'LiveComm.exe' which every 5 minutes or so chatters on the network and causes my XBOX game connection to fail.

If I keep resource monitor open on the PC I can keep my XBOX connection alive if I kill the LiveComm.exe process.

That's how I identified that this was the culprit process ruining my Xbox online experience.

The up-shot is that when I am playing BF3 or Call of duty or any online game I have to disable the network connection on my windows 8 PC.

Why does this service need to consume all of my bandwidth: ADSL 9 Meg connection. It did not do this from first install of windows 8 it only began recently.

Have you tried to block it in the firewall, or disconnect win8 PC from network when you are playing xbox, or streaming video?

Also, the windows 8 Release Preview is available for download (http://www.forumswindows8.com/windows-8-download/). You can do a clean install to fix this issue.

Thanks for answer. I am trying the steps as you said. If that still cant works, I will try RP. Thank you very much.