I'm being asked for a pdf password to convert a file. What is it, if it's not my adobe password?

I have an Asus netbook with windows 10 I'm attempting to convert a book in digital editions to a shockwave format with all to all file converter3000. I'm being told that a pdf password is necessary to complete the conversion. I used my adobe password, but it doesn't work. How can I find out what this password is, or how can I convert a book in digital editions to audio for free?