Select the 'Image.' button, then locate and choose the 'InstallESD.dmg' file.Ĭlick 'Restore' to create the restoration drive. Open the 'Disk Utility' within the Utilities folder under Applications and connect the USB flash drive to one of the ports located on the back side of the iMac.Ĭhoose the flash drive from the left-side tree display and then click the 'Burn' icon.

Expand the 'Show Package Contents' folder.Ĭopy and paste the 'InstallESD.dmg' file to an easily accessible location on the iMac hard drive. Control-click on the 'Install Mac OS X' icon and choose the 'Show Package Contents' icon. Open the 'Applications' directory in Finder. How to Factory Reset an iMac Via Bootable USB Recovery Driveĭownload the version of Mac OS X the iMac is running from the App Store. Select 'Reinstall OS X' from the menu, click the 'Continue' button and follow the on-screen instructions to complete the OS installation process on your clean hard drive. Select 'Mac OS Extended (Journaled)' from the 'Format:' drop menu and enter a name for the hard drive in the 'Name:' text entry field.Ĭlick 'Erase.' to clear all of the hard drive's contents.Ĭhoose the 'Quit Disk Utility' option to exit the disk formatting tool. Select the hard drive on which Mac OS X is installed from the tree list on the left side of the window. Choose the 'Disk Utility' option from the list and click 'Continue.'

Format factory imac