As a rule iTunes uses a library at the path <User's Music>\iTunes\iTunes Library.itl. You can press and hold down shift when launching iTunes to get an option to choose or create a new library if your library is elsewhere for some reason. There are some default lists that an empty library will include, so perhaps you're seeing these. More likely it is because you imported an exported version of the library, but the files weren't in the same paths on the new system as the old one, so while the lists were created no files were added to the library. As I mentioned elsewhere if you move/copy the library correctly there is no need to export or import anything. If you import the files that you already copied over into the otherwise empty library you will get all of the songs, but not the ratings, play counts, playlist membership, etc. that were part of your old library.
Exactly what happens when you add files to the library depends on their location (inside or outside the media folder) and the state of the Keep... and Copy... options under Edit > Preferences > Advanced.
tt2