I had to have my iMac exchanged, and used the migration assistant to pull all my preferences/files/etc from a time machine backup. On my Macintosh HD I now have duplicate folders. For example, I have an "Applications" folder, AND an "Applications (from old Mac)" folder. I also have a "System (from old Mac)" and "User Guides and Information (from old Mac)" folders. Is it safe to delete the "old mac" folders to free up some space? Thanks.