Without some form of hack, you will not be able to run XP HE on the iPod. The iPod is a little more than "just a HDD", as are most HDD based players.
But, if you do manage to do it, it is almost certain that all your tracks, track information and iPod OS will go bye bye
Is it possible to install Windows XP HE on my 30 GB iPod? Because the ipod is just a HDD right? But if I install Windows XP would i lose all my song information and the iPod OS? any help would be great!