Isso resolveu meu problema:
How do I install a Toshiba stack?
This worked on my Mackbook air mid - 2011Windows 7 x64. Be aware that you will loose the "magic scrolling" in case you are using a bluetooth magic mouse. Otherwise all bluetooth devices have been working as a chram with the Toshiba stack.
To make it work, follow this steps: http://linkopia.blogspot.com/2009/05/a2dp-stereo-bluetooth-on-win-xp-boot.html
But instead of downloading the toshiba stack in the above link, download the x64 stack you will find in the link bellow:
http://aps2.toshiba-tro.de/bluetooth/pages/disclaimer.php?dt=bts&download=3-64bit
once you have "tricked" the stacks restart and run the Toshiba assistant