The Download folder on my 2011 Macbook Pro is getting very large. These are mostly .dmg files or .zip Assuming each of these files have been executed, can I safely remove them? As a 35 year DOS user, I still find some tasks on the Mac very difficult. On Windows machines, I generally did all my housekeeping from DOS/Command line. The thing that is driving me crazy is iPhoto and/or Aperture. Where are my pics? They seem to be everywhere. I have quit iPhoto and moved to Aperture, but basically same problem. I now think I must have 3 or 4 copies of all my photos. So can I trash the Iphoto library? Thanks.