Does 7 not use !Pv6 for home networking?
Edit: Yes, from my link
"HomeGroup in Windows 7 is a new way for computers on home networks to associate with each other and to let family members share documents, pictures, music, videos, and printers. HomeGroup relies on IPv6 connectivity and the Windows Peer-to-Peer Networking Platform on computers running Windows 7 on a single-subnet home network."