I have tried doing what I thought was a clean reinstall of Maverick OS. Turning off the Macbook Air. Turning it on whiile holding down Command and R keys. I choose Disk Utility and erase my hard drive. Then I choose the reinstallation option. But it doesn't appear to be a complete reinstall, in that all my stuff is still there. Do I need to download a bootable app and use a USB memory stick/flash drive or external hard drive to install the OS data back to my laptop? Thanks very much for any help.