Fix NS_E_WMP_DRM_CORRUPT_BACKUP (0XC00D11B4) in WMP

You try to play a DRM-protected track or video in Windows Media Player and instead of music you get a dialog: Windows Media Player cannot play the file because the DRM backup is corrupt. Error code 0XC00D11B4, sometimes written as NS_E_WMP_DRM_CORRUPT_BACKUP. This usually shows up right after a Windows update, a drive clone, a system restore, or a profile migration — because all of those copy the DRM license store without keeping its internal bookkeeping consistent. I had a client last month whose WMP broke the morning after an in-place upgrade to Windows 11 23H2; every DRM track from her old Zune Marketplace library refused to play with exactly this code.

What the error actually means

DRM in Windows Media Player isn't a single file — it's a folder full of encrypted licenses plus a backup copy that WMP uses to recover if the primary store gets damaged. When Windows, a backup tool, or a disk imaging utility copies that folder, the two halves can fall out of sync. WMP sees the mismatch, decides the backup is corrupt, and refuses to hydrate the license into memory. So it can't decrypt the media, and it bails with 0XC00D11B4.

The error has nothing to do with your sound card, your codec pack, or the media file itself. Reinstalling codecs will not help. Uninstalling WMP will not help either, because Windows 10 and 11 keep the DRM store outside the WMP install.

The real fix is to delete the DRM folder and let WMP rebuild it from scratch. You lose the local licenses, but they re-download the next time you play or sync a protected file from an authorized source (Groove/Xbox Music legacy accounts, Netflix's old Silverlight DRM, a Zune pass, corporate WMV streams, whatever you've got).

The fix: nuke the DRM store and rebuild

Do this while logged in as the affected user, not as another admin. The DRM folder is per-profile, and deleting it from a different account does nothing.

Close everything. Quit Windows Media Player, Zune, Xbox Music, Groove, the Films & TV app, and any browser tab that might have a Silverlight or PlayReady session open. Also stop the Windows Media Player Network Sharing Service from Services.msc if it's running.
Show hidden files. Open File Explorer, go to View → Show → Hidden items (or Options → Change folder and search options → View tab → Show hidden files, folders, and drives). The DRM folder is hidden, and you won't find it otherwise.
Find the DRM folder. It lives here for the current user:
```
%USERPROFILE%\DRM
```
On most machines that resolves to C:\Users\YourName\DRM. There's also a machine-wide copy at C:\ProgramData\Microsoft\Windows\DRM on some builds, but start with the user one.
Rename it, don't delete it yet. Right-click the DRM folder, rename it to DRM.old. Renaming is safer than deleting because if something goes sideways you can put it back. If WMP is holding a lock you'll get a sharing violation — that means something is still running. Kill wmplayer.exe, wmpnscfg.exe, and wmpnetwk.exe from Task Manager, then try again.
Restart the machine. Don't skip this. WMP checks the DRM store at process start, and a fresh logon makes sure no stale handle is cached.
Launch Windows Media Player and play a protected file. WMP will detect that the DRM folder is missing, create a new one, and re-acquire licenses from whatever source the media was bound to. On a Zune-era library you'll get a fresh license pull; on a corporate WMV with a PlayReady server you'll get a new challenge/response round-trip.
If step 6 silently fails, run the DRM reset utility. Open an elevated Command Prompt and run:

cd "C:\Program Files\Windows Media Player"
unregmp2.exe /ResetDRM

Wait, that path is wrong on modern Windows. Use the actual location:

cd "C:\Program Files (x86)\Windows Media Player"
unregmp2.exe /ResetDRM

The command resets the DRM store to a clean state and forces a re-individualization on the next WMP launch. It's the same thing as deleting the folder, just scripted.

Reset the DRM store from the registry side

If the folder delete didn't take — because a policy is redirecting it, or a third-party tool put it back — check this key and see where WMP is actually pointing:

HKEY_CURRENT_USER\Software\Microsoft\Windows Media\DRM

Look at the DataPath value. If it points somewhere unexpected (a redirected folder, a roaming profile path, an old drive letter from before a clone), that's your culprit. Change it back to %USERPROFILE%\DRM and reboot.

If it still fails

A few things to check before you throw the machine out the window:

Is the media source still alive? If you're trying to play an old Zune Marketplace file and the Zune service is gone, no amount of DRM resetting will help — the license server doesn't exist anymore. Same for any service that shut down and took its DRM issuance with it.
Was the account migrated? Roaming profiles and OneDrive Known Folder Move sometimes sync the DRM folder between machines. That guarantees corruption because the license is bound to the machine's hardware ID. In that case, exclude %USERPROFILE%\DRM from roaming and reset locally.
Check the PlayReady store. For Silverlight/Netflix-era content, the relevant store is here:

%LOCALAPPDATA%\Microsoft\PlayReady

Renaming that folder and relaunching the app triggers a fresh individualization too. I've seen this fix the error when the WMP DRM folder alone didn't do it.

Run SFC and DISM. Not because they'll fix DRM specifically, but because a corrupted drmv2clt.dll or drmclien.dll will produce the same error code. From an elevated prompt:

sfc /scannow
dism /online /cleanup-image /restorehealth

If those come back clean and you're still hitting 0XC00D11B4 on a fresh DRM folder, the media itself is the problem — not the machine. Try playing a known-good DRM file to isolate it. If the good file plays, the broken file's license chain is dead, and the only fix is re-downloading it from the original source.

The whole procedure takes about five minutes. Rename the folder, reboot, play something. That's it. If you're still stuck after all of the above, the DRM ecosystem that issued the license has probably gone dark, and no local fix is going to conjure up a server that hasn't existed since 2015.