i Tunes works really hard to try and fix these problems, but if you're reading this it means that you're running into problems that i Tunes couldn't automatically work out on its own.
Quit out of i Tunes, then delete any of the following files you saw in the first step: “i Tunes Library”, “i Tunes Library.itl”, “i Tunes Library.xml”, “i Tunes Music Library.xml”, “i Tunes Library Genius.itdb”. Now we're adding everything back into a fresh clean library.
Start up i Tunes again, and don't be shocked that your library is completely empty.
In File Advanced, you should allow i Tunes to Keep i Tunes Media folder organized and Copy files to i Tunes Media folder when adding to library.
You don't need to do this, but it will make your life easier and will help prevent problems in the future.
Another important note: There are a couple of features in i Tunes that are on by default on Mac but are normally off on Windows.
If you're unfamiliar with them, you probably should have them turned on, as they will help keep all of your music tidy going forward.There's at least a few types of information that will be lost in the process, which may be considered valuable bits of metadata for some folks: star ratings, “Loves”, play counts, and date added.If you can live without that information, this method tries to preserve everything else about your i Tunes music library.You'll need to know where i Tunes keeps all of its files.Normally, this is in your (home) i Tunes folder but if you're a bit more advanced you might have set it up to be elsewhere and therefore you likely already know where it is.If you know that you had music stored in several different locations, you will want to repeat this step for each. and select the database file that you created in the “Export your library” step earlier.Note that you will end up with duplicate smart playlists that you'll later want to remove. Your entire library is rebuilt with all playlists preserved, and hopefully all problems gone away.Select File Add to Library..., then choose the “i Tunes Media” or “i Tunes Music” folder that you saw earlier.This will take a while to import everything back into your library.The dreaded exclamation points in your i Tunes library!Edited metadata that doesn't show up outside of i Tunes!