Archived - MacBook Air: USB optical drive required for installing Windows with Boot Camp
If you are using Boot Camp on your MacBook Air, you need an external USB optical drive to install Windows.
Boot Camp, MacBook Air, Windows XP SP2 (Service Pack 2), Windows Vista (32-bit versions only)
MacBook Air requires a USB optical drive for the installation of Microsoft Windows Vista (32-bit version only) or Microsoft Windows XP SP2 or later. The Remote Disc sharing software included with your MacBook Air cannot be used to install Microsoft Windows. Connect your external USB optical drive directly to the USB port on the MacBook Air before you start the Boot Camp Assistant.