I wanted to install Quicktime7 but I was getting the message: "This version of Quicktime7 can't be installed on this disk because Quicktime X is already present. Please use Software Update to install..." So I updated all software, even if there was no update for Quicktime. Restarted and tried to install Quicktime7 again and getting the same error. I then decided to remove Quicktime files. I uninstalled my Quicktime, move to trashed, emptied trash and went to Library, find Quicktime folder, moved and emptied trash. Now, my iPhoto won't play video, pictures can only be viewed by thumbnail, iMovie is crashing, and I lost all my videos/movies on iTunes. Can somebody please help me to get them working well again?