AC3 codec not installed (Dolby digital)

[Jeff1461]

I recently purchased a new HP desktop with windows 11 installed, my old desktop was running on windows 10 but with windows withdrawing support for windows 10 I thought the time had come to upgrade.

All was well until I tried to play some home video through windows media player, video quality was stunning but without sound, a banner at the bottom of the screen told me my video file was was recorded using AC3 codec and windows in their wisdom have stopped supporting this format, it did not say why and it would seem they do not care about the millions of frustrated customers who can no longer play video files in their media player, I have trawled my browser looking for a solution to this problem but to no avail, windows simply says to get in contact with HP as they may be able to remedy this.

Has anyone any idea how to solve this frustrating problem (be gentle with me as I am not that tech savvy) Thanks.

[Hawks_Eye · Accepted solution]

Hi @Jeff1461 

Welcome to the HP Support Community! We're here to help you get back up and running.

I completely understand how disappointing it is to upgrade your system expecting improvements, only to find cherished home videos playing in silence. The AC-3 codec was quietly removed from clean installations of Windows 11 24H2, and unfortunately, Windows Media Player no longer supports it out of the box.

Windows 11 no longer includes native support for the AC-3 (Dolby Digital) codec, which causes sound to be missing in videos using this format. You can restore playback by installing a third-party codec pack or using a media player that includes AC-3 support.

Here’s how you can bring back full audio playback:

Option 1: Install a trusted codec pack

You can restore AC-3 support by installing a third-party codec pack that includes Dolby Digital decoding.

• Visit K-Lite Codec Pack
• Choose the Standard or Mega variant (both include AC-3 support)
• Follow the installation prompts and restart your PC

This will enable AC-3 playback in Windows Media Player and other apps that rely on system codecs.

Option 2: Use a media player with built-in AC-3 support

Some media players include their own codecs and bypass Windows limitations.

• Download VLC Media Player
• Install and open your video file in VLC

VLC supports AC-3 natively and plays most formats without needing extra codecs.

Why this happened

Microsoft removed AC-3 from clean installs of Windows 11 24H2, citing licensing and manufacturer pre-installation as reasons. Systems upgraded from Windows 10 may retain the codec, but new devices like your HP OmniStudio X do not include it.

Once you’ve installed the codec pack or switched to VLC, your videos should sound as stunning as they look. If you’d like help configuring VLC or checking if AC-3 is working properly, I’m here to guide you through it.

If my response helped, please mark it as an Accepted Solution! ✅ It helps others and spreads support. 💙 Also, tapping "Yes" on "Was this reply helpful?" makes a big difference! Thanks! 😊

Take care, and have an amazing day!

Regards, 

Hawks_Eye