K-Fresh

Hi, Im having a problem with switch, when trying to convert files from .wma to.mp3. I can add all the files to the convert list fine, but when i click "convert, the following error pops up " Download install-on-demand mp3el". I followed a few links and found the area to download the plugins and got mp3el.exe, but when i tried to run that it asked me which application to run it with and thats where im stuck. Help would be greatly appreciated. Thanks in advance