Hi,
I own a transcription company and have the same problem. None of the people who work for me can get Vista to play their files. Windows does not include the codecs needed to play these files. Even if you get them from another source, get them installed and running, you still can't play the files you need. Some people are having some luck using "switch" to change the files but I have not had sucess with that. Mine still don't play and I have been trying for over a month. I hope the people at Express scribe can recognize that we need to play different kinds of files. .dss and .wav are the most widely used. They are files created by the big dictation systems such as the Orator by Bytescribe. It converts .vox to .wav and then they are downloaded to the transcriptionist.
Jane