Any help with this would be appreciated! So I bought a new mac (MPB retina for anyone who cares) and to save the cost of buying a new hard drive I took the HD out of my old (dead) white macbook, bought an enclosure and use it as an external HD via USB. Which has been amazing as all my old files are completely the place I had left them in when my old macbook died. My question is this; to free up some space on the external hard drive what can I delete? Obviously not my home folder in the users folder, but folders like Library and System on the old HD can they be deleted while leaving all my other files in my home folder still intact and accessible from my new MPB like they are now? Hope this is clear enough and any help would be greatly appreciated!