Newer versions of WMA became available: Windows Media Audio 2 in 1999, Windows Media Audio 7 in 2000, Windows Media Audio 8 in 2001, and Windows Media Audio 9 in 2003.
Der findes flere versioner af WMA-codecet: Windows Media Audio 2 fra 1999, Windows Media Audio 7 fra 2000, Windows Media Audio 8 fra 2001, og Windows Media Audio 9 fra 2003.