Hello, this is my second thread about this topic once i decided to solve my problem using Carbon Copy Cloner. My Mac Pro (mid 2010) came with the Grey (Machine specific) Install DVD 10.6.4, i was updating it through the Software Update utility till reach 10.6.8. Currently this is the OS X version installed in my main HD and running without any problem. As i have lost or misplaced the original Grey DVD shipped with my Mac, my goal is to create a bootable disk, partition, Disk image, DVD, or USB flash memory... with just and only the necessary operating system content. In other words: something as closer as what you get after a clean OS X Install ( i guess the Admin Settings and maybe other folders should be included together with the System Files, no idea what they would be tho.) I want to do this cose my current main HD (which it will be the source of the cloning) uses 975 Gb, too heavy for my purpose that is only to keep a bootable clean 10.6.8. (I do not know what weight it would have, 150 Gb? less?) I would appreciate some clues about what kind of content may i omit in order to get the less heavy (but still bootable and fully usable) clone of my main HD. Thanks in advance.