I've made a big mistake, I need to add file extensions en masse.
I've just been renaming my MP3 collection, and downloaded a software that renames via ID3 tags. Unfortunately, while doing what I asked it to do, via my own fault I have caused it to get rid of the .mp3 at the end, so now I am stuck to renaming all of my 4,000 files unless someone can tell me how to fix this.
I'm really irritated with myself for doing this. I've just made a problem even worse. If anyone knows how I can leave the file name intact while just adding the *.mp3 to the end, that'd be great.