Cleaning up from too much data is always possible. It is recovering when too much has been irretrievably deleted which presents a challenge.
Ignoring what is on the disk to start with, are you happy that that library contains all of your playlists and files that you think it should, and do they play when you try?
The key parts of the structure that I can see from your screenshots are these:
- My Music
- iTunes
- iTunes
- iTunes Media
- iTunes Music
- iTunes Media
where 1,2 & 6 make up the active library (which potentially references some content stored in 4 & 5) while 3,4 & 5 look like legacy content.
Hmm. Fiddling about probably hasn't helped. It looks like you've moved iTunes Music up a layer which might have broken links to any content that was stored in it. Might be best to move that back before doing anything else.
Under Edit > Preferences > Advanced turn Keep organized off. Click OK, then turn it back on again. This should reorganize anything that is inside the designated media folder (My Music\iTunes\iTunes Media) into the correct place. When this is finished you can check the iTunes Music folder for any content that might be missing from your library that you want to add to it. Move this into My Music\iTunes\iTunes Media\Automatically Add to iTunes if found, then discard what remains of the iTunes Music folder.
Have a look inside My Music\iTunes\iTunes Media\Mobile Applications. and My Music\Test itunes Is there anything in the second folder which isn't also in the first one? If so you can use the Automatically Add to iTunes folder. Alternatively you can redownload any apps that are missing from your library from your purchase history. You can now discard the Test itunes folder.
Any duplicates in the library? See Re: How to remove duplicate songs.
You might also want to try my script CleanDeadApps if there is any sign of multiple copies of the same app in your Mobile Applications folder.
I also recommend iTunes Folder Watch with its option to check for dead tracks on startup as a way to make sure that everything in your library works, and everything in the media folder is connected to iTunes.
Last, but not least, see Backup your iTunes for Windows library with SyncToy to make sure you have an easily updatable backup.
tt2