An M3U file is a playlist of songs. It is a standard textfile so you can edit it with notepad. You would want to make one if you were making an auto-play MP3 CD. Here is a .BAT file for making one. Right-click on it below, save it into your directory of MP3 songs, then run it from explorer. The file it creates will include all MP3s from that directory and all sub-directories, therefore if you run it on the root of your harddrive it would include all MP3s on the whole drive.

 

Download MAKE_M3U.BAT