Fix WMDRM Error 0XC00D28AC: Unsupported Protocol

Quick answer

Error 0XC00D28AC means your Windows Media DRM (WMDRM) components are outdated and can't talk to the license server. You need to update or reinstall the DRM module, not Windows.

What's actually happening

You're trying to play a DRM-protected file — maybe a movie from an old subscription service, a rented video, or a music track you bought years ago. Media Player contacts the license server to get the rights, and the server rejects the request because your DRM version is too old. The protocol version in the error name (NS_E_DRM_UNSUPPORTED_PROTOCOL_VERSION) tells you exactly that: the handshake between your machine and the server uses a version the server no longer supports.

Microsoft hasn't shipped a new WMDRM update since Windows 7, so on Windows 10 or 11 the built-in DRM is usually fine. The error shows up when the DRM store is corrupted, when a third-party codec pack has replaced the files, or — most commonly — when you're trying to play content that uses a newer DRM scheme (like PlayReady) that WMDRM simply doesn't understand. I've seen this on a fresh Windows 11 install of an old Dell OptiPlex where the user tried to play a DRM-protected WMV from a 2008 Zune Pass download. The file was fine; the DRM protocol was ancient.

Fix 1: Update the WMDRM components

The first thing I'd try is forcing Windows to refresh the DRM files. It sounds simple, but it works more often than a full reset because it replaces the corrupted store without wiping your licenses.

Open an elevated Command Prompt. Press Win + S, type cmd, right-click Command Prompt, and choose Run as administrator. You should see a black window with a prompt that starts with C:\Windows\system32>.
Type this command and press Enter:
```
regsvr32 wmdrmsdk.dll
```
You should see a dialog that says "DllRegisterServer in wmdrmsdk.dll succeeded." Click OK.
Now type:
```
regsvr32 wmnetmgr.dll
```
You'll get a similar success message. If you get an error like "The module was loaded but the entry-point DllRegisterServer was not found," skip to Fix 2 — that file isn't registered the same way.
Restart your computer. Don't just close the window — a full restart clears the DRM cache.
Open Windows Media Player and try the file again. The error should be gone if the store was just stale.

Fix 2: Reset the DRM store

If the registration didn't help, the DRM folder itself is probably damaged. Resetting it wipes all previous licenses, so you'll need to re-download or re-authorize any purchased content. That's a pain, but it's the only reliable way to clear a corrupted store.

Close Windows Media Player completely. Check Task Manager for any wmplayer.exe processes and end them.
Open File Explorer and navigate to:
```
C:\ProgramData\Microsoft\Windows\DRM
```
You might need to enable hidden items (View > Show > Hidden items).
Rename the DRM folder to DRM_old. Do not delete it — you might need the backup if something goes wrong.
Create a new empty folder named DRM in the same location.
Right-click the new folder, choose Properties, go to the Security tab, and click Edit. Make sure SYSTEM has Full control. If not, add it and check the box.
Restart your PC. Windows will recreate the DRM files on first use.
Open Media Player, play a DRM file, and let it re-acquire the license. You'll see a prompt to download the license — click Yes.

If you're on Windows 10 or 11 and the DRM folder doesn't exist, that's normal — those versions moved the store. Skip to Fix 3.

Fix 3: Install the PlayReady update (Windows 10/11)

On modern Windows, WMDRM is mostly a legacy shim. The actual DRM work is done by PlayReady. If you're hitting 0XC00D28AC on a recent build, the PlayReady runtime is either missing or too old.

Open Settings > Apps > Optional features.
Click Add a feature, search for Media Feature Pack if you're on Windows N editions. Install it if it's not there.
Run Windows Update. Check for updates, install everything, and reboot.
After reboot, open PowerShell as admin and run:
```
Get-AppxPackage *PlayReady* | Select Name, Version
```
You should see a package listed. If nothing shows up, your PlayReady is missing — download the Windows Media Feature Pack from Microsoft's site for your build.

If that still doesn't work

At this point, the content itself might be the problem. Some services have dropped WMDRM entirely. If you're trying to play a file from a defunct store like the old Zune Marketplace, no amount of fixing will help — the license server is gone. In that case, the only option is to find a DRM-free copy or use a converter, but check the legality in your region first.

Also try a different player. VLC can handle some DRM-free WMV files, though it won't touch protected ones. If VLC plays it, the file isn't actually DRM-protected and you're dealing with a file association issue instead.

Prevention

Don't install codec packs like K-Lite or Shark007 unless you really need them. They often overwrite the WMDRM DLLs with older versions, which triggers this exact error. If you already have one installed, uninstall it, then re-register the DRM files with the commands in Fix 1. And if you're still buying DRM-protected media, stick to services that use PlayReady or Widevine — WMDRM is on life support, and this error is only going to get more common.