What does HRESULT 0xC00D11C7 (NS_E_WMP_AUDIO_CODEC_NOT_INSTALLED) mean?

NS_E_WMP_AUDIO_CODEC_NOT_INSTALLED

Diagnosing NS_E_WMP_AUDIO_CODEC_NOT_INSTALLED in the Windows Media Player playback path

NS_E_WMP_AUDIO_CODEC_NOT_INSTALLED (0xC00D11C7) is returned when no installed audio decoder accepts the stream media type required by the Player operation.

Record what the Player had already completed because later retries often replace the original evidence. The specific rejected condition is no installed audio decoder accepts the stream media type required by the Player operation.

Controlled playback comparison

1. Start from the original call and log 0xC00D11C7 together with its object and operation phase.
2. Collect format tag or subtype GUID, WAVEFORMATEX, candidate decoder list, bitness and graph connection result before changing the machine.
3. Use this single-variable test: decode a short elementary stream with the same media type and inspect filter/DMO enumeration.
4. Repeat on a fresh object if the original predates a configuration, device or resource change.
5. Validate the expected next operation, not just initial open or object creation.

Actions that obscure the cause

• installing a video codec pack.

Technical references

• Supported protocols and file types
• Using Windows Media in DirectShow
• Working with codecs
• DirectShow filters
• Microsoft HRESULT registry