[SirGalahad92]

Looks like it works for WMP Legacy like its supposed to.
When [x] WMP settings is enabled, I get the error code 0xc00d5212 and then it asks to purchase the HVEC codecs from the microsoft store.
I'm sure there's just one more step needed to get this working for it. Any ideas?

[Shark007]

WMP Legacy and the Media Player App are 100% different software's and share exactly zero code between them.
My codec software supports WMP because it can use Directshow codecs but the Media Player App uses Media Foundation Codecs which are distributed below.
To use the Media Player App, the checkbox for [] WMP settings needs to be unchecked.

Codecs for the Media Player App are available below.

The following are from Dolby Laboratories
AC4 Media Foundation by Dolby Laboratories v1.0.0.0 Aug 14, 2024

AC3 Media Foundation by Dolby Laboratories v1.1.285 Aug 14, 2024

The following are from Microsoft
Microsoft Dolby Atmos (AC3) v21600.1 This contains both Media Foundation and Directshow codecs

Media Foundation MPEG2 v1.2.12.0 Sept 11, 2025

Media Foundation HEVC v2.4.13 June 26, 2025

Media Foundation AV1 v2.0.4.0 Sept 11, 2025

Media Foundation VP9 v1.2.6.0 May 23, 2025

Web Media Extension v1.2.14 Aug 9, 2025

HEIF Image Extension v1.2.22 Aug 9, 2025

RAW Image Extension v2.5.5  Aug 9, 2025

Webp Image Extension v1.2.10 Aug 9, 2025

After downloading the file, double-click on it to install.

If the Media Player App continues to fail, and as long as my codecs are installed, Windows Media Player will play everything you have.
To get WMP Legacy to play everything, choose to use the checkbox [x] WMP suggested settings (hovering this checkbox reveals more information)