Windows M4b Player → «TRUSTED»

VLC Media Player is the most reliable tool for simply opening an M4B file. Audibly — Audiobook Player - Microsoft

A true "Windows M4B player" must remember your position.

If you have a massive library and use Apple mobile devices, iTunes is hard to beat for functionality. However, on Windows, it is notoriously heavy, slow, and resource-intensive. If you only want to listen on your PC, iTunes is likely overkill.

If you are a power user who likes to customize their interface and doesn't mind a slight learning curve, foobar2000 is the best Windows M4B player for you. However, for the casual user, it can feel a bit "techy" and dry.

One reason to avoid Windows Media Player is chapters. A good Windows M4B player lets you jump from Chapter 5 to Chapter 12 instantly.

AIMP is a Russian-developed audio player known for its 32-bit audio processing and massive skin library. It handles M4B well if you enable "Save playback position."

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

Microsoft recently replaced Groove Music with a new "Media Player" app (blue icon). Does it fix the M4B issue?

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.