:-) UPDATE: I found the aacdec.exe to download at http://www.nch.com.au/components/index.html
:-( But, on the last file I was converting I got a message that it needed another add-on, ffmpeg11.exe. There is no .exe to download of that name, just ffmpeg, ffmpeg2 and ffmpeg3.
:-( I then tried to install WavePad and convert through that program but also got the same message, need ffmpeg11.exe. So I'm at fail.
Now what? Thanks