Fix NS_E_CURLHELPER_NOTRELATIVE (0XC00D1330) URL Error

What's Going On?

You're trying to play a media file or stream in Windows Media Player (WMP), and instead of your music or video, you get this:

NS_E_CURLHELPER_NOTRELATIVE (0XC00D1330) – The specified URL is not a relative URL

This error means WMP got a full web address (like http://example.com/song.wma) when it was expecting just the file name or a path relative to your current folder (like song.wma or \Server\Share\song.wma).

I've seen this most often when someone copies a link from a website or tries to open a playlist (.asx, .wpl) that points to an absolute URL. WMP's older URL parser just chokes on it.

Fix #1: The 30-Second Check — Fix the URL

Before you go poking at settings, verify what you're actually opening. This is the real fix 9 times out of 10.

1. Right-click your media file or playlist and select Properties.
2. Look at the Location or Target field. If it starts with http://, https://, ftp://, or mms://, that's your problem. WMP can't handle a direct absolute URL in a context that expects a relative path.
3. If it's a playlist (.asx or .wpl), open it with Notepad. You'll see lines like:
   <REF href="http://site.com/file.wma" />
   That's the absolute URL causing the error.

What to do next:

• For a single file: Download the file to your computer first, then open it from your local drive. Don't open the web link directly in WMP.
• For a playlist: Open the .asx or .wpl file in Notepad. Change the absolute URL to a local file path. Example: Change href="http://site.com/file.wma" to href="C:\Music\file.wma". Save and reopen the playlist.

Expected result: After saving and reopening, WMP should play the file without the error. If it still throws the error, move to the next fix.

Fix #2: The 5-Minute Fix — Reset Media Player Settings

Sometimes WMP's internal URL cache or settings get corrupted. Here's how to flush them.

1. Close Windows Media Player completely. Make sure it's not running in the system tray.
2. Press Windows Key + R, type regedit, hit Enter. The Registry Editor opens.
3. Go to this key:
   HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Player\RecentURLList
4. Right-click RecentURLList in the left pane and select Export to back it up (just in case). Save the .reg file somewhere safe.
5. Then right-click RecentURLList again and choose Delete. Confirm yes.
6. Also delete this key if it exists:
   HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Player\URLHistory
7. Close the Registry Editor.
8. Now reset WMP to defaults. Press Windows Key + R, type %appdata%\Microsoft\Media Player, hit Enter.
9. Delete everything inside that folder. Don't worry—WMP will recreate these files when you start it again.
10. Open Windows Media Player again. It will act like the first time you ran it. Go to Tools > Options (if you don't see the menu bar, press Ctrl + M).
11. On the Network tab, make sure Use proxy settings for streaming media is checked (but if you're on a corporate network, leave it as-is).

Expected result: After doing this, WMP should stop throwing the 0XC00D1330 error. Try opening your media again. If it still fails, let's go deeper.

Fix #3: The 15-Minute Fix — Reset Windows Media Player via Settings

This is the nuclear option. It reinstalls WMP and clears all caches, playlists, and libraries. Only do this if the other steps failed.

1. Press Windows Key + I to open Settings.
2. Go to Apps > Apps & features.
3. Scroll down and click Optional features (on Windows 10 20H2 and newer, it's under Apps > Optional features).
4. In the list of installed features, find Windows Media Player. If you don't see it, WMP might already be disabled—skip to step 7.
5. Click it, then click Uninstall. Wait for the uninstall to finish.
6. Restart your PC.
7. Go back to Settings > Apps > Optional features.
8. Click Add a feature at the top.
9. Scroll down and check Windows Media Player, then click Install.
10. Wait for the installation to complete. Restart your PC again.

Expected result: WMP is now factory fresh. Open your media file—the error should be gone. If it's not, the issue is in the media file itself, not WMP.

Last Resort: Use a Different Player

I'll be honest: WMP is old. Microsoft stopped updating it after Windows 8. If you keep hitting this error with streaming URLs, skip WMP entirely. Download VLC Media Player (free, open-source). It handles absolute URLs, relative URLs, and everything in between without complaint.

To use VLC instead:

1. Download and install VLC from videolan.org.
2. Open VLC, press Ctrl + N, paste your absolute URL, and click Play. That's it. No errors.

That's the pragmatic fix. But if you're stuck on WMP for some reason, the three fixes above should get you sorted. Start with Fix #1—it's almost always the answer.