I had a huge problem with this because of trying to keep my music library on 3 different computers, with different OS's and different music programs. What I ended up doing is clearing everything from my iTunes library, but not deleting the songs from my hdd. Then going into the folder they are stored in and searching for things like *-1.mp3, *-2.mp3, etc since my other music programs were making copies of the songs and adding -# to the end of them. That got rid of most of the duplicates. Then re-importing everything.
two ways. first go through one by one and delete the duplicates (simply click and press the delete key on your keyboard. second way if you have your music backed up (in another location besides your Itunes library file) you can simply delete the entire library (click the first song then press "SHIFT" and click the last song then press delete) then drag the files from the backup location and drop to iTunes.
well since itunes likes to copy paste all your songs into one folder delete the old folders and duplicates should be gone, also note it copies ALL your music into its folder so you might even free up a few gigs of hdd space....
Thank you. If I delete all the songs the hook up my ipod and import them I should be fine right?