Hi MR, Sorry if this has been asked many times before – a search turned up a few results, though none really answered my question very clearly. I've just moved from an iMac to an MBA. I have an external hard drive with several partitions: 1) For Time Machine Backups 2) A Carbon Copy Clone (of my old iMac) 3) For storage of iTunes Media and other miscellaneous files I haven't yet activated Time Machine on the MBA, so the TM partition on the external drive only contains the Backups.backupd folder from my iMac. I have simply starting using my new MBA from a clean install and am using the Carbon Copy Clone of my iMac to copy files over as I need them. To get to the point of this post, I hoped someone might be able to give me clear instructions as to how I can delete the entire Time Machine backup of my old iMac before activating TM on the new computer. I am aware of the "Browse Other Backup Disks…" option when option-clicking the Time Machine icon in the menubar, but am not sure where to go from there. TL;DR: How do I delete the entire TM backup history of an old computer? Thanks in advance.