Hi,
CDA is a file extension for a CD Audio shortcut file format. Used by Microsoft Windows to refer to audio tracks on a CD, a CDA file doesn’t contain audio but is simply a shortcut to the tracks on an audio disc.
CDA files are files created by the computer's CD drivers which point to the location of a track. MP3 is a file type which uses compression to save space. To convert CDA file to MP3 first make space for your files. You require a folder for the music to go into as well as enough space to store all of the music you wish to copy through the process of 'ripping.' Choose a software program such as Windows Media Player. Double-check your setting. You will need to look for settings to let you specify the place you wish to save the files and in what format. Finally copy the files.
Please feel free to reply if you face any issues with Windows in future