And dont answer "microsoft windows" cause i know that. Who is the interpreter? Iths an awesome .wma found at C:\WINDOWS\system32\oobe\images on a typical windows xp computer
When you first either get a new computer with Windows XP or reinstall XP, that stuff has to do with the menu that comes up that helps you set your internet and usernames and stuff, right before you actually start using Windows XP for the first time.
It really should delete that folder though once it's finished; those are just one-time/temporary files.
And to answer your question, Microsoft is the composer of that music, just like they are with the startup/shutdown sounds and logon/logoff sounds.