Under the Volume Scheme heading set the number of partitions from the drop down menu to one.Click on the Partition tab in the DU main window. After DU loads select your newly installed hard drive (this is the entry with the mfgr.'s ID and size) from the left side list.Select Disk Utility from the main menu and click on the Continue button.Wait patiently - 15-20 minutes - until the Recovery main menu appears. Restart the computer and after the chime press and hold down the COMMAND-OPTION- R keys until a globe appears on the screen. Assuming the former:Р”В«e sure you backup your files to an external drive or second internal drive because the following procedure will remove everything from the hard drive. If you don't have a Recovery HD on the Time Machine backup from which to boot, then what you do next depends on whether your computer came with Lion or later pre-installed or not. Once the drive is formatted select the option to Restore a Time Machine backup.Partition and format the new hard drive using Disk Utility from the Recovery HD's menu.When the Utility Menu appears select Disk Utility.Select the icon for the Time Machine backup drive. Boot from the hidden Recover HD by restarting the computer and at the chime press and hold down the OPTION key until the boot manager screen appears.If you wish to boot from it in order to fully restore a Time Machine backup, then: It does have a bootable, hidden copy of the Recovery HD installed on your computer. You should be aware that a Time Machine backup is not bootable.

Before using mac time machine