You'd better convert m4a to mp3 for mp3 format is one of the most popular audio formats. As for how to convert m4a to mp3, just follow below tutorial.
To convert M4A to MP3 without iTunes but via Windows Media player is also a good method. Windows Media player can play various kinds of media files, like WMV, WMA and MKV and MP3. This player is also useful when it comes to converting M4A to MP3. You can read through this part to see how to make it.
1. Run Windows Media player on your PC and then add the M4A files to this program via dragging and dropping directly. Thus, the files will be shown in the library of this software.
2. Hit on the "Organize" button at the top left of the interface and then choose "Options" tab to click on.
3. On the panel that shows up, you need to hit on "Rip Music" and then drag down to hit on the "Change" button to choose a proper folder for the converted MP3 files.
4. Move to the "Format" area and then click on the box under it to choose "MP3" as the target format via scrolling down. You are also able to set the bit rate for the output MP3 audio files. Click on "OK" button to confirm your settings.
As you can see, you can get the converting task done with this solution with high efficiency. Have a try and you will know how simple this method is.
For more methods, check: How to Convert M4A to MP3 without iTunes http://www.leawo.org/tutorial/how-to-convert-m4a-to-mp3-without-itunes-1387.html#part1