As per Cesar from zuneinsider the zune is not compatible with vista right now, but will be when the consumer edition is publicly available in January and will also include 64bit vista support.

So, if you are already running vista and don’t want to wait then there is a solution. Paul from modoco has found a way to get zune running on vista. I haven’t tried it myself, but users at modco forums have claimed that it works. Good luck.