Fix NS_E_DEVICE_NOT_SUPPORT_FORMAT (0XC00D0FA3) in WMP

That error is maddening, I know

You double-click a video, Windows Media Player opens, and then—boom—nothing. Just a pop-up with NS_E_DEVICE_NOT_SUPPORT_FORMAT (0XC00D0FA3). You've got something to watch, and WMP is throwing a tantrum. Let's fix it.

The fastest fix: install a codec pack

Windows Media Player is picky. Out of the box, it only plays a handful of formats natively—WMV, ASF, and some AVI files. The moment you try an MP4 (especially H.264 or HEVC) or an MKV file, it chokes. That's the 0XC00D0FA3 error. The file's container or codec isn't supported.

The real fix is the K-Lite Codec Pack. It bundles every codec WMP needs. Here's what to do:

1. Go to the K-Lite Codec Pack site (codecguide.com). Download the Basic version—it's all you need for this error.
2. Run the installer. Pick Lots of stuff as the preset mode (this gives you everything without overthinking).
3. Leave all default settings. Click next until it finishes.
4. Restart WMP. Try playing the file again.

If that doesn't work—and it should for 90% of cases—skip ahead to the conversion step below.

Why does installing a codec pack work?

Think of Windows Media Player as a DVD player. It can spin any disc, but if the disc uses an encoding it doesn't understand, you get a blank screen. A codec pack installs the decoders—the software that translates your video file into something WMP can display. K-Lite covers H.264, H.265/HEVC, MPEG-4, FLAC, Opus, and dozens more. Once those decoders are in place, WMP stops complaining.

I've used this on Windows 10 and 11, from version 1909 through 23H2. Works the same every time. Don't bother with the official Microsoft HEVC extension from the Store—it's $0.99 and often doesn't fix MKV or MP4 files with non-standard audio tracks. K-Lite is free and more comprehensive.

When the codec pack isn't enough

Sometimes the file itself is corrupted or uses a really obscure codec. I've seen this with old DivX files from the mid-2000s or with video recorded on weird surveillance cameras. In those cases, you have two options:

Option 1: Switch players (the practical choice)

Stop fighting WMP. Download VLC Media Player (videolan.org). VLC plays almost everything without codec packs—it has its own built-in decoders. Drag your file onto the VLC window. If it plays, you're done. If it doesn't, the file is corrupt.

I prefer VLC for anything WMP can't handle. It's lightweight, no bloat, and updated regularly.

Option 2: Convert the file (for stubborn cases)

If you're dead set on using WMP, convert the file to a format it likes. Use HandBrake (free, handbrake.fr) to convert your video to MP4 with H.264 video and AAC audio—WMP handles that combo like a champ.

1. Open HandBrake. Load your problematic file.
2. Under Presets, choose Fast 1080p30 (or whatever matches your resolution).
3. Click Start Encode. This takes a few minutes.
4. Open the converted file in WMP.

That's it. The error disappears.

Less common causes you should know about

This error isn't always about codecs. Here are two edge cases I've run into:

• DRM-protected files: Some video files (especially from iTunes or Amazon) have digital rights management that WMP can't handle. If you got the file from a paid service, check if you need their proprietary player. No codec pack will fix that.
• Corrupted file header: A partially downloaded file can trigger this error. Try downloading it again from the source. In my experience, this happens most often with torrents that stopped mid-download.

How to prevent this error going forward

Honestly? Use a different player as your default. I keep WMP around only for legacy WMV files. For everything else, VLC or MPC-HC (Media Player Classic Home Cinema) handle modern formats better. If you really want to stick with WMP, install the K-Lite Codec Pack after every fresh Windows install—that way you never see 0XC00D0FA3 again.

Also, always check the file extension before you double-click. If it's .mkv or .mov, expect this error in WMP. A quick rename won't fix it—codecs aren't determined by file extensions. The container format is baked into the file's structure.

One more thing: keep Windows and WMP updated. I know, updates are annoying, but Microsoft occasionally releases codec-related patches through Windows Update. They're rare, but they happen.

That should get you past this error. If it doesn't, reply below with the exact file extension and codec info (you can check with MediaInfo, a free tool). I'll help you narrow it down.