What triggers this error
You're trying to save a playlist or add a song to your Windows Media Player library. Suddenly you get that popup: "It is not possible to store a value in a namespace node that has a different security type" with the code 0XC00D1397. This usually happens right after you've moved your music folder to a new drive, or you've changed where Windows stores your user files. It also shows up when you try to save a playlist to a network drive or an external USB stick formatted with FAT32 while your Windows runs on NTFS. I've seen this dozens of times on Windows 10 machines where people have moved their Documents folder to a different partition.
What's really going on
Windows Media Player expects your library folder to have the same security settings (called "security descriptors") as the original location. When you move your media folder to a drive that uses a different file system or has different permission rules, the player can't write its internal database files there. The error message is Microsoft's way of saying "Hey, this folder doesn't trust me the same way the old one did." It's not a virus or a broken player — it's a permission mismatch.
The fix — step by step
Pick one of these methods. I recommend Method 1 if you're not scared of making a small folder change. Method 2 is the nuclear option but always works.
Method 1: Reset the folder permissions (fastest)
- Close Windows Media Player completely. Check your system tray (the bottom-right corner) to make sure it's not minimized.
- Press Windows key + E to open File Explorer.
- Go to
C:\Users\YourUserName\Music— replace "YourUserName" with your actual username. - Right-click the Music folder and choose Properties.
- Click the Security tab at the top.
- Click the Advanced button near the bottom.
- In the new window, look at the top for the owner's name. It should say your username. If it says something like "TrustedInstaller" or "SYSTEM", click Change next to it.
- Type your username in the box, click Check Names, then click OK.
- Check the box that says Replace owner on subcontainers and objects.
- Click Apply, then OK on all windows to close them.
- Open Windows Media Player again. Try saving your playlist now. It should work.
After step 10, you might see a progress bar that lasts a few seconds. That's normal — Windows is updating permissions for all the files inside the Music folder.
Method 2: Move your media library back to default
- Open Windows Media Player.
- Click the Organize menu (top-left corner). Choose Manage libraries > Music.
- You'll see a list of folder locations. If your Music folder points to a non-default location (like D:\Music or a network path), select it and click Remove.
- Click Add, then browse to
C:\Users\YourUserName\Music. Click Include folder. - Click OK to close the window.
- Now open File Explorer and go to C:\Users\YourUserName\Music. Copy all your music files from the old location into this folder.
- Open Windows Media Player again. Press Alt key to show the menu bar. Click Tools > Options > Library tab.
- Click Monitor folders. Make sure only C:\Users\YourUserName\Music is listed. Remove any other locations.
- Click OK twice. The player will rescan your music. Try saving the playlist now.
If it still fails
Check if your drive is formatted as FAT32. Right-click the drive in File Explorer, choose Properties, and look at the file system line. If it says FAT32, Windows Media Player can't write its security info there. You have two choices: reformat the drive to NTFS (this erases everything, so back up first), or keep your music library on an NTFS drive. I've never seen this error on a proper NTFS drive with the right permissions. If you're using a network share, make sure the share has write permissions for your user account — check with the network admin. Also, scan your system with Malwarebytes just to rule out any infection messing with permissions. In rare cases, a corrupted user profile causes this. If nothing works, create a new local user account and try again.