Install digital format conversion software. Restart your system before converting a file after the installation.
Find the MP3 file you are looking for on your system or download by right-clicking and choosing save as. If the MP3 file is on a CD or flash drive, save it to your hard drive. Converting from a media source can cause a crash.
Open the audio conversion software. There will be a button that says BROWSE or ADD FILE, which will navigate you to the folder of the MP3 file you want to convert. Choose it and hit OK or ADD.
Select the destination format as M4A or MPEG4. Most software will be able to convert a multitude of formats. Be sure the output format MPEG4 conversion preset is 44100Hz if available.
Select CONVERT NOW or EXECUTE command button and the file will begin its conversion to MP4.