What to do when AVI files show missing codec 0xC00D5212 error

What the error 0xC00D5212 means

When you try to play an AVI video, Windows may show a code like 0xC00D5212. This error usually means your computer doesn’t have the required decoder to decode the video or audio inside the AVI container.

Common causes

• The AVI uses a codec that isn’t installed on your system.
• The file uses a codec that isn’t widely supported (for example older DivX, Xvid, or H.264 in AVI).
• The file is corrupted or only partially downloaded.
• A media player is missing support for that container/codec.

How to fix the error

Identify the missing codec

Use a tool such as MediaInfo to inspect the AVI and see which video and audio codecs it contains. If you know the codecs, you know what to install.

Play with a codec-friendly player

Programs like VLC or MPC-HC include many codecs built in and can often play AVI files without additional installs.

Install codecs carefully

If you prefer a codec pack, choose a reputable one such as the K-Lite Codec Pack (Standard or Mega) and install from the official site. Restart your player after installation and test. Be aware that codec packs can cause conflicts with already installed software, so proceed with caution.

Convert the file

If you can’t play the file, converting to a more universal format (for example MP4 with H.264 video and AAC audio) can help. Tools include HandBrake or FFmpeg. In HandBrake, choose the AVI as the source and output MP4; select a widely supported preset.

Check for file integrity

If the file was downloaded or copied, try the transfer again or obtain a fresh copy. Test on another device or user account to rule out hardware or profile issues.

Additional tips

Keep Windows and DirectX up to date, and ensure your antivirus didn’t flag the file. Use trusted sources for downloads and avoid installing optional software unless you need it.