Most of my iTunes library will not play.
I keep getting the message, "original file can't be found"
Windows, Windows 10
That message appears when iTunes can no longer find the file for that piece of music.
The music is not "in iTunes". Instead, the file for a piece of music is stored on your computer and when you added it to your iTunes Library you told iTunes where that file was located. Every time you ask iTunes to play that piece of music, or copy it to a device (such as an iPhone etc., iTunes looks for and uses that file.
If the file gets moved, renamed or deleted, or the path to the file is renamed or deleted, then iTunes will be unable to find the file and the message you see will be shown.
So the question is, what happened? Did you, or another computer programme, move, rename or delete the files? Another possibility is if you told iTunes to look on an external drive, such as a memory stick or hard drive, but that memory stick or hard drive is no longer connected to your computer (or it now has a different drive letter).
Once we know what happened, we can hopefully take steps to restore the music to your library. In basic terms, you will need to move the files back to their original location, or undelete them.