Clarification: Carbonite is a cloud based full time, automatic data backup. So the day my laptop went down, I had a complete backup of all sub directories and files below User (Mark).
Of the 3 iTunes data problems (podcasts, apps and music), I had resolved podcasts (by sheer luck) per my previous message yesterday. Any further resolutions (music and apps) will occur only by my inserting the proper (restored) directory/file(s) within the existing structure C:\Users\Mark\Music\iTunes that I restored from Carbonite yesterday or C:\Users\Mark\AppData that I'm currently downloading.
It has been my understanding that the (*.itl) file "iTunes Library 2012-12-02.itl" (date stamped the day my machine died: 6/28/15) either carries all the data for one's iTunes music library or is a file pointer to the local location of the library (my library is located: C:\OneDrive\My Sounds\iPod Nano Music (or, taken to one of several dozen end of path examples) C:\OneDrive\My Sounds\iPod Nano Music\Bob Dylan - Highway 61 Revisited\01 - Like A Rolling Stone.mp3.
I inserted the file per the following path: C:\Users\Mark\Music\iTunes\iTunes Media\iTunes Library 2012-12-02.itl. No tunes appeared in iTunes suggesting to me that I likely placed the file under the incorrect subdirectory? Where should the .itl file be located? I presume there's no way of directly pointing iTunes to the music file as you had showed me previously with podcast files (Edit/Preferences...)?
If I end up having to start from scratch reloading tunes from the drive to iTunes I don't suppose there a way to reverse the process and send all the tunes currently on the iPod Nano to iTunes?
I'm currently chasing my tail with apps. I have zero apps in iTunes (probably had 50 or so). All the apps that I've been using are installed on the phone (about a 1/3 of the total). Although I likely have a cloud phone backup, it would be useless since a restore would merely give me back what I already have on the phone--not what I need--an iTunes app restore. I visited iCloud and saw no icon remotely resembling an iTunes/app backup?
So, absent your direction regarding the location of an iTunes apps backup, I'm back to digging through my Carbonite backups. I've researched this app problem and it seems that apps may not reside (Windows 7) under C:\Users\Mark\Music\iTunes\...\ but would be found under a completely different User subdirectory: C:\Users\Mark\AppData which is huge and currently downloading from Carbonite's servers to my desktop. If apps are located under AppData, do you know the app parent subdirectory?