I'm helping a friend and I'm a little lost with why there is almost NO storage left on their iMac with a terabyte hard drive. I've ran a application call "omni disk sweeper" and I didn't see anything out of the ordinary. If you go to "about this mac" click on storage there is a little over 700GB of data (in yellow) taking up space. I know they do some Time Machine backups but they use a external USB drive to back up everything. The total of the back up says that its almost 981gb of data! However if you go to the "Macintosh HD" in the finder window there is nothing out of the ordinary that I can see. They have their music of about 150gb's, 70gb of his business documents/photos, 12gb's of photos, etc all of totaling 225.26GB which is exactly what omni disk sweeper came back with. I'm thinking it may have something to do with them previously have Boot Camp and he MAY OR MAY NOT have deleted the partition correctly. But I went into Disk Utility and there isn't a Boot Camp partition any longer. They also use to use Fusion to run Windows so they could run a version of Quickbooks for their business. I believe he deleted it but not sure how or what he did to remove it but its no longer being use and I only see some minor files or about 30gb for Fusion but that 30gb is included in that overall 225.26GB of total storage space I've found. Something I'm missing or I don't know exactly what I'm doing but I cannot find where this data is. Ideas or suggestions?