reinstalling itunes

after a couple days of itunes 7.0.1 crashing whenever i synced my ipod i thought i would try to reinstall it not knowing this was a stupid idea. first i deleted it out of my applications folder and then from the library. it wouldnt let me reinstall 7.0.1 so i put in my osx panther discs and reinstalled it from there but now i have itunes 4.6 installed

when i try to upgrade it, it wont find anything. i'm guessing because i already did have it installed. i looked at my software updates and it says it has installed it already. is there anyway i can reinstall it or get to that file to delete it so system update will reinstall it