If files have mysteriously disappeared, run a full scan of your computer with up-to-date antivirus software. (Or, if it’s on a network, connect to the network first.) Or, if your library is on an external drive, make sure the drive is connected to your computer before opening iTunes. If you don’t find songs by searching, check the Recycle Bin. Drag songs (or folders containing songs) to the iTunes window to add the songs to iTunes again. Go to Start > Search, then search for a song by title or artist. If that doesn’t work, your songs may be elsewhere on your hard disk.

If the iTunes Library file was included, you also see your original playlists. Locate your iTunes folder (by default in your PC’s Music folder), then drag it to the iTunes window. To make your songs appear in the iTunes window again, try the following in this order: If a song used to appear in iTunes but doesn’t now, it may be because the iTunes Library file was moved, or the song was moved from the iTunes folder.

Move your iTunes library to another computer.

Add and edit information about items in your library.

Turn on your device’s accessibility features.

Back up your iPhone, iPad, or iPod touch.