Tom recently upgraded to Windows 10 and he's really happy with it. Now he's turning his attention to his Mac. It started notifying him that he's losing disc space, but when he went to check the storage space on his computer, it has a huge folder labeled "Backup." Leo says it sounds like OS X is backing up his data to his local hard drive. Tom should just go into the System Preference pane and disable Time Machine. Leo recommends SuperDuper instead. He likes it because he can boot to the external backup should the original drive die. It's a great feature.
Another good utility is called Disc Inventory X, which will show him what the space on his hard drive is being devoted to. He can see what kinds of files are taking up all that space.