1) I downloaded Lion from the App Store and installed it on my Macbook Pro. 2) I DID NOT save the disk image (is it still there somewhere? if so, what's the file name?). Someone gave me an offer I couldn't refuse for the computer, and I need to leave Lion on it, but remove all of my personal files and info. How do I get a clean install of Lion on my computer? I've already backed up the whole drive to Time Machine, and just for safety's sake, I manually put all of my important files on a separate external hard drive as well. I tried to search, but all of the results skipped steps that I need. It was basically just "I downloaded it and made a disk image". I don't know where to find the Lion .dmg file, AND I obviously wasn't able to do that before I installed it. Any help would be greatly appreciated.