Fix NS_E_DRM_BACKUP_CORRUPT: Restore WMA/WMV Licenses

You're trying to back up an old WMA file or play a WMV you downloaded (legally, from a store that shut down ten years ago) and Windows throws NS_E_DRM_BACKUP_CORRUPT (0XC00D2743). The exact message says one or more backed-up licenses are missing or corrupt. I've seen this on Windows 7, 8, and 10 machines—usually when someone tries to restore a DRM backup after a fresh OS install or when Media Player's DRM store got partially deleted by a cleanup utility.

What actually causes this

Windows Media DRM keeps licenses in a hidden folder: C:\ProgramData\Microsoft\Windows\DRM. That folder contains the encrypted licenses tied to your media files. When you back up licenses (Tools > Options > Privacy in WMP, or the old DRM backup tool), it writes a set of files. If any of those files are truncated, zero-byte, or half-written—say, your antivirus scanned mid-copy or the backup was pulled from a dying USB stick—the restore process fails with this error.

Another common trigger: you've got a corrupted DRMv2.bak or Indiv02.key file. That last one is the DRM's individualization key, and if it's missing or corrupt, Windows can't validate any license, period. This isn't a license-expiry issue—it's a file corruption issue.

The fix: reset the DRM folder and start fresh

There's no repair tool for this. The real fix is to delete the entire DRM store and let Windows rebuild it. You'll lose any licenses you backed up—but if they're corrupt, they're useless anyway. If you have media purchased from a store that still exists (rare), you can re-download them. For old files, the licenses are gone forever, but at least the error stops.

1. Close Windows Media Player and any app that uses DRM (like old Zune software or Windows Movie Maker). Check the system tray for WMP icons.
2. Open File Explorer and go to: C:\ProgramData\Microsoft\Windows\DRM. You'll need admin rights. If you don't see ProgramData, type the full path in the address bar.
3. Delete everything inside that folder. Don't delete the folder itself—just the files and subfolders. This includes DRMv2.bak, Indiv02.key, and the backup subfolder if it exists.
4. Reboot the machine. Not strictly required, but it clears any lingering handles.
5. Open Windows Media Player again. It'll see no DRM store and create a fresh one. You'll get the 'Playback of this file requires a license' prompt—that's normal.

If you actually need the backed-up licenses

Sometimes the backup files are fine, but the folder's permissions are off. That happens after an OS restore where the security descriptors didn't carry over. Try this before nuking everything:

1. Right-click the DRM folder > Properties > Security.
2. Make sure SYSTEM and Administrators have Full Control.
3. Click Advanced > check 'Replace owner on subcontainers and objects' and set owner to Administrators.
4. Apply, then try the backup restore again.

I've had two clients where this alone fixed it—the files were intact, but Windows couldn't read them because the ACLs were garbage.

Still failing? Here's what to check

• Is your date/time correct? DRM licenses have validity windows. If the clock is off by more than a few days, Windows rejects the license. I've seen a motherboard battery die cause a 2008 date—no DRM file survives that.
• Did you run the backup on a different OS? Windows 7 DRM backups are not fully compatible with Windows 10. If you're restoring an old backup onto a new OS, it'll often fail with this exact code. Your only option is to re-license the files.
• Third-party DRM tools like 'DRM Backup Tool' or 'Digital Rights Management Cleaner' sometimes leave junk. If you used one, uninstall it, then reset the folder.
• Check for antivirus interference. Some security suites quarantine Indiv02.key because it looks like a suspicious executable. Go to your AV's quarantine list and restore it, then try again.

If none of that works, you're out of luck with those specific files. But the error won't affect new DRM content—Windows will just write clean licenses going forward. Last month I spent an hour with a client whose entire old Christmas music collection was locked this way. We reset the DRM folder, lost the licenses, but at least the error stopped popping up every time they opened WMP. Sometimes you've got to cut the loss.