I thought this was pretty amusing, see pic and instructions.
Whoever created the sound file on your standard windows install used a cracked version of SoundForge.
For those who want to check it out, open C:\WINDOWS\Help\Tours\WindowsMediaPlayer\Audio\Wav \WMPAUD1.WAV in a hex editor and go all the way to the bottom to see the tag from Deepz0ne, apparently the guy who wrote the crack.