Windows Vista Speech Recognition Tutorial - Welcome Sequence Sound (READ DESCRIPTION!)
This sound is WELCOMESEQUENCE.WAV, used for the Speech Recognition tutorial in Windows Vista. InfinityPlusOne shown this as Windows Vista Beta 1 startup sound which isn't true at all. Longhorn/Windows Vista Beta uses Windows XP sounds (builds 5469 - 5840.16384 added a few of the sounds that appear in the final release). If you still think Longhorn sounds is real, go try out a Longhorn build yourself.