You don't care about how the drive works, do you? What you are asking will get you answers about motors, magnetic head pickups, perhaps even answers about air currents and "flying head" distances.
What I think you want to know is where should your iTunes files be placed.
That is a simple move, of some files or files, from one location on the drive to another.
Sounds like the Staples tech got your file(s) over to the new computer. But without those files actually being in their correct place, then your iTune installation can not find your music.
I can't tell you that, I don't use iTunes, but I am sure someone here will be able to inform you.
To actually move those files should only take a few minutes. Having 20GB of files is fairly massive (I approximate it to be about over 5000 songs). But when you drag a file from one location to another location, on the same hard drive, then the action only renames the path "from where" > "to where." It doesn't have to rewrite much. It will be a fraction of a second, times those 5000 files, and thus I guess in a minute or two all those files can be relocated.
Just where is/are your files? and where to move them to?
I have a new computer (compaq presario, 500gb HD) using windows 7. When 'staples' did the data transfer from my (old)Dell Dimension 2400, they mistakenly goofed on transfering my 'Apple i-tunes library', to where now I can't listen to my music/audiobooks. I phoned Apple tech support, they said I would have to tranfer myself with an external Hard Drive. The problem is, I've never done it before and am unsure how it works. The library contains 20gb of music/audiobooks using (i-tunes 9.0), and I don't want to pay $150.00 (unless it's absolutely my last option)for someone to come to my home to do it. I'm sure it's fairly easy but I need some help to guide me on what to do now? Staples refuses to help or take responsibility for their error, and have been rude about the whole situation. I'm on my own. Thanks JC