NS_E_PROPERTY_READ_ONLY (0XC00D32CC) Fix for Windows Media

You're editing a Windows Media file—maybe adding album art, changing a title, or tweaking metadata in a script—and out pops NS_E_PROPERTY_READ_ONLY (0XC00D32CC). This usually happens in three scenarios: you're using Windows Media Player's library, a custom PowerShell script, or a C# app that calls the Windows Media Format SDK. The error means the property you're trying to set is flagged as read-only, so the system refuses to take your change.

Why does this happen? Windows Media files can carry properties that the OS or the file's own header locks down. The most common culprit is DRM—digital rights management. If a file is protected, almost every metadata field becomes read-only. But it can also happen with plain MP3s or WMAs if the file itself has the read-only attribute set, or if you're using Windows Media Player 11 or 12 and the file is in a monitored folder that's marked as read-only. I've also seen it when people try to update a property that the SDK defines as read-only by design, like MFPROTECTED or WM/DRM fields.

Before you go down a rabbit hole, check the simplest thing first. Right-click the media file, hit Properties, and look at the bottom of the General tab. If the Read-only checkbox is checked, uncheck it and hit Apply. That alone fixes it about half the time, especially if you're not dealing with DRM.

Fix 1: Remove the Read-Only Attribute

1. Locate the file in Windows Explorer.
2. Right-click it and select Properties.
3. On the General tab, uncheck Read-only.
4. Click Apply, then OK.
5. Retry your metadata edit.

If the file is in a library folder, the folder might be read-only. Do the same for the folder: right-click, Properties, uncheck Read-only, apply to all subfolders. This is a known mess in Windows 10 and 11, where folders sometimes get marked read-only for no good reason.

Fix 2: Use a Different Editor

If the attribute clears but the error persists, the read-only flag is likely baked into the file itself. Windows Media Player's built-in tag editor is limited and often triggers this error for no obvious reason. Try a third-party tool like MP3Tag or Windows Media Encoder 9—yes, it's old, but it still works for stripping DRM and rewriting metadata. Download MP3Tag, open the file, and try changing the same property. If it succeeds, the issue was WMP's editor, not the file.

Fix 3: Check for DRM

DRM is the stubborn one. If the file has a lock icon in Windows Media Player or plays only on your PC, it's likely DRM-protected. DRM properties are read-only by design—you can't touch them without a license. If you own the file and want to remove DRM, use Windows Media Player's Burn feature to burn it to a CD, then rip it back. That strips DRM but also re-encodes, so you lose some quality. It's a workaround, not a fix, but it gets the job done.

Fix 4: Script and SDK Workarounds

If you're writing code, don't try to set a read-only property directly. Instead, check the property's flags first. In the Windows Media Format SDK, use IWMHeaderInfo::GetAttributeFlags and look for WMT_ATTR_READONLY. If it's set, either skip it or throw a clear error to the user. PowerShell users can check with Get-ItemProperty but honestly, the attribute is unreliable—better to just catch the error and tell the user to edit manually.

// C# example
IWMHeaderInfo headerInfo = (IWMHeaderInfo)reader;
ushort streamNum = 0;
WMT_ATTR_DATATYPE type;
ushort attrLen = 0;
byte[] value = new byte[1];
headerInfo.GetAttributeByIndex(0, ref streamNum, null, out type, out attrLen, value);
// Check flags
if (flags == WMT_ATTR_READONLY) {
    // Don't bother trying
}

If It Still Fails

After all that, if the error won't budge, the file might be corrupt or protected at the filesystem level. Try copying the file to a new location (like your Desktop) and editing it there. Sometimes the original file's ACLs block writes even when the read-only checkbox is off. Also, run sfc /scannow if you suspect system files—rare, but I've seen it fix WMP component issues that cause this error.

One last thing: if the file is a Windows Media Video (WMV) and you're trying to edit a property like WM/ContainerFormat, that's not even meant to be touched. You'll hit this error every time. Know what you're setting and why. When in doubt, use a dedicated metadata editor and avoid the SDK unless you're building something serious.

That's the full picture. Start with the read-only attribute, move to DRM, and don't waste time on properties that are read-only by design. If you're still stuck, drop a comment below—I've fixed hundreds of these and I'm curious what your specific file is doing.