For me it plays whatever OS I boot into...
Well obviously since it plays right after the machine completes the POST it will sound before it goes to the bootloader and/or before it loads whatever the default OS is set to.
I can only assume the OP wants to use it as the startup sound IN Vista.
I actually do recall seeing it somewhere as an audio file but it was obviously recorded from the speakers of a Mac so it didn't have the best sound quality.
You could do that yourself.