Fix NS_E_WMG_NOTALLOUTPUTSRENDERED (0xC00D1057) in Windows Media Player

Quick answer — if you're in a hurry

Run regsvr32 wmdrmsdk.dll and regsvr32 wmvcore.dll in an admin Command Prompt, then delete the %ALLUSERSPROFILE%\DRM folder contents. Reboot. That's covered in step 3 below.

Why this error happens

This error code (0xC00D1057) shows up in Windows Media Player when it tries to play a file and can't render some outputs — typically audio tracks or protected streams. I first ran into it years ago with a ripped DVD that had multiple audio languages. The player choked on the second audio track because its DRM license had expired or the codec was corrupted.

The real trigger is almost always one of two things: a broken DRM (digital rights management) license store, or a missing/corrupt audio codec. Windows Media Player uses DRM to manage playback of protected files — think purchased music from the old Zune store, or some archived Windows Media Audio (WMA) files. If the DRM store gets corrupted after a Windows update or software conflict, the player can't validate the license and throws this error.

Codec issues are more common with older AVI or ASF files that use non-standard audio compression. I've seen it with files encoded with Fraunhofer IIS or old ACELP codecs. The error message is vague — "Not all outputs rendered" — but the fix isn't complicated.

Fix steps (numbered)

1. First, identify the problem file. Right-click the file in File Explorer, select Properties, go to the Details tab. Note the audio format. If it's WMA or WMV Pro, it's DRM. If it's something exotic like "Windows Media Audio 9 Voice" or "ACELP.net", it's codec-related.
2. Close Windows Media Player entirely. Check Task Manager for lingering wmplayer.exe processes and end them. This prevents file locks.
3. Reset the DRM store. This is the fix that works for 80% of cases. Open Command Prompt as Administrator. Run these commands one at a time:

   regsvr32 wmdrmsdk.dll
   regsvr32 wmvcore.dll

   Then navigate to C:\ProgramData\Microsoft\DRM. Delete everything inside that folder. Yes, everything. Windows will recreate the files when you open WMP again. Reboot before testing.
4. Re-register all WMP components. If step 3 didn't clear it, open an elevated Command Prompt and run:

   for %x in (%windir%\system32\wmploc*.dll) do regsvr32 %x

   This bulk-re-registers all WMP locale and core DLLs. I've seen this fix stubborn cases after a Windows 10 22H2 update.
5. Check for missing codecs. Download and install the K-Lite Codec Pack Standard (version 18.4.0 or newer). During install, select "Lots of stuff" under audio codecs. This adds support for rare audio formats like Windows Media Audio Voice and ACELP.net. Reboot after install.
6. Test with a different file. Find a standard MP3 or WAV file. If that plays fine, the issue is specific to that original file — likely an expired license. If all files fail, repeat steps 3 and 4.

Alternative fixes if the main one fails

Sometimes the DRM store is too corrupted to fix. Try these in order:

• Use the Windows Media Player Settings reset tool. Go to Control Panel > Programs > Turn Windows features on or off. Uncheck "Media Features", reboot, re-check it, reboot again. This nukes all WMP settings including DRM.
• Switch to a different player. VLC Media Player (version 3.0.21) handles protected WMA files better than WMP in my experience. It bypasses the DRM check for local files. Not a fix per se, but it gets the job done.
• Run the Windows Media Player troubleshooting tool. In Windows 11, search for "Find and fix problems with Windows Media Player" in Settings. In Windows 10, it's under Control Panel > Troubleshooting > Programs > Windows Media Player. I've had mixed results — it works about 30% of the time.

Prevention tip

Keep your DRM store healthy: avoid running WMP from USB drives or mapped network drives, which can corrupt the license cache. Also, uninstall any old codec packs (like the old DivX bundle) before installing new ones — conflicting codecs are a common cause. And if you're still using Windows 7, upgrade already. The DRM subsystem in Windows 7 is ancient and prone to this error with modern media files.