no iTunes library in iPhotos Source pop-up menu

no iTunes library appears in iPhotos Source pop-up menu when making a slideshow. I've tried re-opening everything in the order suggested, I've tried removing my iTunes library to the desktop, which was a disaster, took me 3 days to get iTunes to work properly again! Not doing that again. Have thought about re-downloading it but Mac store tells me that my iTunes was not purchased from Apple.... huh? Who elses would do it