Answer

Windows 11 versions prior to 24H2 include native support for the AC-3 audio codec, also known as Dolby Digital, allowing audio files with the “.ac3” extension to play directly through Windows' default media player without any additional software.

Starting with Windows 11, version 24H2, Microsoft has stated that the AC-3 decoder is no longer included in the operating system by default. See Microsoft's Codecs in Media Player support article for more information on this change.

This article applies to MSI notebooks running Windows 11, version 24H2.

 

 

 

Recommendation: Install a Third-Party Media Player for “.ac3” Playback

1. Download and install KMPlayer or VSO Media Player from the developer's official website.

2. Open the “.ac3” audio file using the newly installed media player.

Success check: The “.ac3” file plays back with audio through the newly installed third-party media player.

 

Common Questions (Q&A)

What is the AC-3 codec, and why did Windows stop including it by default?

AC-3, also known as Dolby Digital, is an audio codec used to decode “.ac3” audio files. Starting with Windows 11, version 24H2, Microsoft removed the AC-3 decoder from the operating system's default codec set; refer to Microsoft's Codecs in Media Player support article for the official explanation of this change.

 

Why do some MSI notebooks still support AC-3 while others don't?

MSI notebooks that ship with Windows 11, version 24H2 preinstalled from the factory retain native AC-3 support as part of that factory image. Notebooks without a preinstalled operating system, or that have had Windows 11, version 24H2 freshly (clean) installed, use Microsoft's standard installation, which no longer includes the AC-3 decoder by default.