Voice Over IP providers , provide you with a service to listen to your voice mails held on the system via email. Usually there’s a choice between MP3 ( Which costs money due to the licensing fee) , VML or .WAV ( Uncompressed so large file size ) .

Usually there will be an online portal for you to login to via Internet Explorer and download an Active X control to be able to play the files through a browser. This control will download a player usually stored in  C:\Windows\System32\VMPlayer.exe , where you can associate .vml’s to in your operating system. However for some reason in Windows 7 the player does not work if you try and open a .vml file with it. If you open the VMPlayer and open the VML file by searching for it it does.

Evening following through the file association instructions here http://www.dslreports.com/faq/12328 , it still crashes when you try and open the vml file through the VMPlayer. The only resolution I found to this was to switch the voicemail file type to .WAV ( or MP3 ) and let Windows media player or another media player take care of the audio!