You can download a codec from http://www.orban.com/plugin/ that will that will allow

Windows Media Player to play almost all m4a, mp4 and AAC variant files and streams.

The Codec is compatible  with Windows Media Player

versions 6.4 / 7.x / 8.0 / 9.0 /10.0 and 11.0

on systems running Windows Vista, XP and 2000.