Sorry but as Windows 8 has many issues I found an under 20 buck pocket router to use when using AD HOC.
Good question and I've subscribed to see what the other answers are.
recently I got a new laptop installed with windows 8. When I try to join any locally created ad hoc network(created from another laptop loaded with widows 7) to play multiplayer games(no internet connection involved) it shows limited connectivity instead of connected. when I inspected the wireless properties, I noted that my laptop sends packet but not receiving anything in return. so I tried to give ipv4 address manually rather than acquiring automatically. now my laptop both seds and receives data, but still it shows limited connectivity. I couldn't join the game. if anyone has the answer, plz d o reply. thanks