Convert M4B to a playable format?

Another shill.

Open iTunes, find the files, highlight them, right-click, Convert to Mp3.

Or go into iTunes settings for Importing, change the default to mp3 at 192 kbps or above (more hi-fi). Burn the m4b files to a CD and rip the CD with iTunes.

Don’t pay for a media converter touted by a shill exhuming a very dead thread.