The dongle is recognized without problems in W7 but to use a Bluetooth A2DP device must install a driver that is not provided by Daffodil (although the packaging leashes think that the dongle also supports the A2DP devices. Specifically looking for in Google "a2dp cambridge Silicon Radio Ltd. Komeil "you should get on the blog: http://blog.komeil.com/2009/05/installing-bluetooth-headset-in-windows.html that gives you the drivers and explanations.
It is not very normal Daffodil not fourbisse these drivers on their site or at least a link to the drivers. Google helps well but only once it has identified the drivers that Cambridge Silicon Radio Ltd. can work with this dongle.
Hoping to help you, this information was found in the product review on Amazon UK. Note that the transmission quality is not excellent generates noise in the helmet, for 5 euros it is perhaps not surprising, not to use for music lovers so.