When you double-click an M4B file on Windows, the OS tries to open it in Windows Media Player or the "Movies & TV" app. Both will play the audio, but That is a nightmare for a 40-hour novel.

Always test your M4B files in VLC first. If VLC can't play it, no other player will. If VLC can play it but forgets your position, you forgot to check the "Remember playback position" box in the advanced settings.

Users who want something free, lightweight, and immediately effective.

VLC is the Swiss Army knife of media players. While it defaults to music mode, enabling M4B support requires a simple settings tweak.

If you have a collection of loose MP3 files and want to turn them into a single, polished M4B book, you can use specialized tools: