My friend has a Macbook Pro (2012) and she was using it a while ago when she was prompted to update her OSX, she went to update and her computer died. Since then she hasn't been able to access anything, It reads: "An error occured while preparing the installation. Try running this appilication again." Anytime she try to update my OSX so she can access her files. Is there anyway I can reinstall the OS without losing all of of her files? Also, if anyone knows of a way I can just manually update the MacBook without having to reinstall the OS, that would be the optimal choice. Sorry guys, I don't use apple products often at all andhonestly, I don't really know anything about how to repair them. Any advice (in Lamens terms please) would be much appreciated! Thanks in advanced guys!