I have a MacBook Pro that I had my iPhoto library on until a few months ago. I wanted to free up space and move my 50+GB library to a Seagate external drive. That worked fine. Over the past month, I had my college aged daughter work on deleting bad photos by plugging in the external drive to my MacBook Pro or our iMac. Now somehow the whole library is on my MacBook, and on my external drive, and on my iMac. She said to start out with it asked her what library to open. (I named it Correct and set the computers actual libraries to DoNotUse). Now iPhoto Correct Library exists in all 3 places, and the actual GB size differs on all 3. I am scared to delete and delete the wrong one that might be just thumbnails or some other unusable files. (Not really sure on what iPhoto completely saves). Was there something in the settings that caused it to duplicate the libraries? My daughter is a Video Communications student that has been migrating from PC to Mac. I slowly converted her earlier this year to an iPad, an iPhone, and then bought her the virtually unused used iMac as her college video production lab is all Mac-based(And an amazing one at that). I am trying to preach the virtues of Mac and now their software is making me pull out our hair! Whatever happened she did it inadvertently and we can't seem to Google an answer or a solution. But I need to fix it! I have a couple thousand digitally converted photos from old family slides and don't want to import them and start working with organizing them until I get rid of the bad libraries. But since this is my entire families and my moms entire families photo library I don't want to make a mistake on the deletion. Thanks in advance for any suggestions!