Garbled words, music plays fine

I have a Creative Zen Vision:M 30GB. I have not used it in over a year and have no idea where my software is (if I have any). I got a new computer and connected it to download more music. It seemed to download fine, but when I listen to it, it is all garbled. The music plays fine, but the words are unintelligable. Even the old stuff that used to play fine is doing the same thing. I downloaded the recovery tool, but it did not help in the least.