User Guide
Page 49
... your MacBook Air: 1 Make sure your user account. Use Disk Utility to erase the internal flash storage. You can also review detailed instructions in the following Knowledge Base article: http://support.apple.com/kb/HT3910 Installing Applications You can open Disk Utility (/Applications/Utilities/Disk Utility) and choose Help > Disk Utility Help...
... your MacBook Air: 1 Make sure your user account. Use Disk Utility to erase the internal flash storage. You can also review detailed instructions in the following Knowledge Base article: http://support.apple.com/kb/HT3910 Installing Applications You can open Disk Utility (/Applications/Utilities/Disk Utility) and choose Help > Disk Utility Help...