I have a Podcast...I just can't listen to it

So I used Allen's idea of creating a commercial for one of the classes I teach, English 151, by having two sections of the same course give a brief line or two of commentary. They discussed what the course consists of and what future students of the class can expect. I thought if it turned out well, I could use it on my website and potentially have future classes listen to it during the first week of the semester. After editing it at home, eliminating all of the ummms and the awkward pauses, combining the commentary from both classes into one file, and saving the changes, I somehow can't listen to the new version...only the old ones. Apparently, I have to download something or other onto my computer, but I just haven't had time to figure out what yet. So to make a short story long, my podcast is still forthcoming!