The updated versions of the Mac OS X operating system are not available as DVDs, but still, you can start or boot up your computer device to an installation and can run different Disk Utility operations. Like, if you want to reinstall Mac OS X on a MacBook and want to clear all the data off the computer, you can simply use Disk Utility in order toreformat the laptop’s internal hard drive. Before reformatting the MacBook, you need to be sure that you back up all data that you wish to retain. For more information, you can take help from the experts at AppleMacBook Support Number. Find out the steps given below in order toreformat a MacBook- First of all, you need to restart your MacBook and then hold down the Command and R keys when the gray startup screen appears. Now, you are required to click on the "Disk Utility" option. After this have to click "Continue." Here, simply highlight internal hard drive of your MacBook from the list on the left side of the window. In the next step, go to the “Erase tab” located at the top of the window. Further, you have to set the format type to "Mac OS Extended," and then simply enter a name for the hard drive that will be reformatted. Then, you need to click the "Erase" button.