Hey all, I just want to make sure I don't inadvertently delete all of someone's documents and such. OS X (Mountain Lion) isn't booting, and recovery isn't working. So I want to use a USB installer I have, but it's for Mavericks. The MacBook is capable of running Mavericks of course, but will installing it (without formatting the MacBook HD) erase the drive anyway? I know it's a stupid question, I'm 90% sure I can install Mavericks over Mountain Lion and keep the documents/music/pictures/etc in tact, I just want to be SURE. Thanks!