I had a G5 running OS 10.4.11 with a 160Gb Hard drive and an extra 320Gb Hard drive inside the tower. I was running a back up using a Western Digital My Book Studio Edition with a 500Gb Hard drive. Recently the G5 died and I picked up a Mac Mini 2.53 GHz Core 2 Duo processor running OS 10.6.8 with an internal 320 Gb Hard Drive. I plan on picking up an external enclosure for the extra 320Gb hard drive that I had added to the G5 tower. I already restored most of the content from the WD My Book to the Mac Mini's internal 320Gb drive. I was using the software that came with the Western Digital My Book (WD Anywhere Backup) to run the back up on the G5. Since OS 10.6.8 has Time Machine I'll either use that or the WD Anywhere Backup to run the back up for the Mac Mini. The WD Anywhere Back up software basically copied everything over and created the same folders as were on the G5. My main question is, how does Time Machine work? Does Time Machine do the same and create duplicate folders on the back up hard drive or does it do it differently? Also if I decide to use the WD Anywhere Back up software to run the Mac Mini back up it will create a new back up and write over the existing files/folders on the WD My Book drive I have. Will Time Machine behave the same way or will I be able to just have it continues the back up without having to re-write the back up all over again. It is time consuming. Also how does Carbon Copy Cloner work? Is it a better back up program then Time Machine? Any help will be appreciated.