Audacity Forum

The safest thing you can and should do-is make a full backup of the files before working with them. Keep the copy completely off-line. Should you make an error, it can be recovered by reloading. I treat all files as irreplaceable and thus do this. The media you use for the copy is also important for...

I would keep at least 1 gigabyte free. A 45 minute WAV file will not be that large, but you will need room if editing. Another point is that you are going to create an MP3, which regardless of bitrate will be very small by comparison.