Fix: MP3 files are saved with incorrect file extension when downloaded

When downloading .mp3 files using Internet Explorer or any other browser, the Save As dialog may add an incorrect file extension (.mp2 or .mpeg, instead of .mp3). Whenever this happens, you need to change the file extension to .mp3 manually.

If this problem happens when downloading .mp3 files from a particular website, then the webserver may be sending the wrong MIME type for .mp3. With that said, it’s a server-side setting that needs to be fixed by the administrator.

On the other hand, if this issue occurs for every website, the content-type registry setting in your system might be incorrect.

Solution

The following procedure fixes the MIME settings for .mp3, .mpeg, and .mpg file types on all versions of Windows — including Windows 10.

1. Open Notepad and copy the following lines into it.

   Windows Registry Editor Version 5.00
   
   [HKEY_CLASSES_ROOT\MIME\Database\Content Type\audio/mp3]
   "AutoplayContentTypeHandler"="MusicFilesContentHandler"
   "CLSID"="{cd3afa76-b84f-48f0-9393-7edc34128127}"
   "Extension"=".mp3"
   
   [HKEY_CLASSES_ROOT\MIME\Database\Content Type\audio/mpeg]
   "CLSID"="{cd3afa76-b84f-48f0-9393-7edc34128127}"
   "Extension"=".mp3"
   
   [HKEY_CLASSES_ROOT\MIME\Database\Content Type\audio/mpg]
   "CLSID"="{cd3afa76-b84f-48f0-9393-7edc34128127}"
   "Extension"=".mp3"
   
   [HKEY_CLASSES_ROOT\MIME\Database\Content Type\audio/x-mp3]
   "CLSID"="{cd3afa76-b84f-48f0-9393-7edc34128127}"
   "Extension"=".mp3"
   
   [HKEY_CLASSES_ROOT\MIME\Database\Content Type\audio/x-mpeg]
   "CLSID"="{cd3afa76-b84f-48f0-9393-7edc34128127}"
   "Extension"=".mp3"
   
   [HKEY_CLASSES_ROOT\MIME\Database\Content Type\audio/x-mpg]
   "CLSID"="{cd3afa76-b84f-48f0-9393-7edc34128127}"
   "Extension"=".mp3"

2. Save the file as mp3_mime_fix.reg
3. Run the file mp3_mime_fix.reg by double-clicking on it. Click Yes when asked for confirmation.

Set WMP as the default player

Alternately, you can set Windows Media Player as the default (via Default Apps).

On earlier versions of Windows, use Default Programs to set WMP as the default.

1. Click Start → Default Programs → Set program access and defaults.
2. Click Continue when you see the User Account Control (UAC) prompt.
3. Click Custom to expand the section.
4. Under Choose a default media player, select Windows Media Player.
5. Click OK.

This not only sets Windows Media Player as the default player for media files in the system but also fixes incorrect MIME settings for many file types automatically.