How do I create an iTunes library ITL file for recovery and locate missing album folders?

Additional .itl files are saved in a Previous iTunes Libraries folder when and if an update to iTunes changes the internal structure of the .itl file. If you don't have a Previous iTunes Libraries folder where you are looking you might not be looking at the path of your previously active iTunes library, which is the one that I would expect to get opened most often, and is most likely to have been updated at some point. For example if you've moved the library from one computer to another your active .itl library could have been at say E:\Music\iTunes\iTunes Library.itl rather than C:\Users\<User>\Music\iTunes\iTunes Library.itl which is the default path. You could search the whole computer for files of the form *.itl to make sure you haven't overlooked a more complete backup of your library.

File > Add Folder to Library can be used to add all of the content of your media folder to an otherwise empty library, that may or may not be displaying your purchase history in the cloud. If you've already imported all of your media then there is no need to do that again. Playlists are only held in the .itl so reimporting doesn't rebuild those.

You can copy and paste your .itl file when iTunes is closed in order to create a backup copy that you could go back to at a later date if needed. For a more complete approach that covers the media as well see Backup your iTunes for Windows library with SyncToy - Apple Community.

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See Empty/corrupt iTunes library after upgrade/crash - Apple Community. A key detail is that you cannot simply click on files in the Previous iTunes Libraries folder to open them, you must hold shift while launching iTunes and use the Choose Library... option. Ideally you want your active library in the main iTunes folder and called iTunes Library.itl which is why I suggest copying and renaming the .itl files from the outset. You might also have a .tmp file that holds the last known good copy of your lost library. If all else fails you can import the tracks you have into an empty library with File > Add Folder to Library. The tracks in your media folder aren't discovered automatically, you have to do something, however doing this won't restore playlists, ratings, play counts, playlists, etc. so restore an earlier library file if you can.

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