Forgot the admin password in Mac OS X? Well, Apple let’s you boot computers into what is known as Single User Mode. To boot a Mac into Single User Mode, boot the machine holding down Command-S. Once the system boots up, you should see a command prompt. Here, run fsck: fsck -fy Then mount the file system: mount -uw / Then reset the password using the passed command passwd <username> For example, if the user is root: passwd root When prompted, provide the desired administrative password.