Question : Problem: Itunes backup and recovery

I am in need of a better understanding of what info is housed in the itunes livrary file and what role it specifically plays.  

It seems Itunes automatically looks certain places for songs and this often leads to a great deal of file duplication with unknown targets.

I am trying to backup itunes exactly the way it is now and reinstall it as a mirror image on a new hard drive.  

Specifically , here is an oddity I notice.  The user had a folder on the desktop with 10GB of songs and other stuff.   The library file apparently knew about this folder but , I assume,  wants the folder in location it thins it should be.   Now that I have moved that folder in the process of restoring it, it is in the my music folder with all the other itunes stuff.

Also , what is best way to go about backing up purchased music and restoring.  I dont think all his purchased stuff came over.

Answer : Problem: Itunes backup and recovery

There are two folders where ITunes stores the information
iTunes Library.itl
iTunes Music Library.xml
That are located in "C:\%User%\My Music\iTunes\"
The .itl is the actual library
As to my knowledge ITunes only stores the path of the file, and doesn't copy the file.
You can set up Itunes to consolidate your library, that means that ITuens will search yor computer for music and will move the files to the default location, normally
"C:\%User%\My Music\iTunes\iTunes Music"
If you open the iTunes Library.it with a word procesor, delete it's contens and save it again with a 0 byte length upon starting ITunes you'll get a notice telling you that the library is corrupt and Itunes will try to recrate it from iTunes Music Library.xml

So if you know the old path and the new one clean the .itl, open the xml and do a search & replace to change the old path with the new path, and then OPEN ITunes.

If you lost the files then open ITunes, menu>Add folder and add the folders with the music, the library will be updated