http://www.sofotex.com/iTunes-Library-Updater-(iTLU)-download_L31772.html
On both PC and MAc it is very labor intensive to erase all the broken links or duplicate items. this software does it instantly! I was so happy it actually worked I thought I would share it for those who have had the same frusterations.
For the mac there is this application as well...
http://dougscripts.com/itunes/itinfo/dupin.php?page=1

