I recently installed Mac OS X Lion (Golden Master) on an external USB drive to try it out. I thought that the drive was empty, but I apparently installed it on a drive that had some files on it. This morning, when I bought Lion on the Mac Store and set everything up, I plugged the USB drive and saw that it had OS X files on it. I want to delete all traces of the GM from that drive so that there are no conflicts. I have already deleted these folders: Applications Library System Users Do I have to do anything else to remove all traces of the GM? Thanks.