I've been trying on and off for about six months to get my Apple Wireless Bluetooth keyboard working on Vista 64. The first part of the puzzle was finding a bluetooth dongle that had support for Vista 64. Most only support Vista 32. Here's the one I found:
Twelve quid from Novatech. The key thing is that it has a Widcomm chipset.
That was only half of the story. Getting an Apple device working on Vista is like getting a camel through the eye of a needle. Both companies are pig headed when it comes to claiming that they are right and someone else is wrong I'm sure!
Enter this blog article which sorted it all out for me.
My only concern is what happens after 3 hours if the keyboard goes to sleep. I'm sure I'll work it out :)