Knowledge base

MacBook Air (Mid 2011): Gray screen, black screen, or prohibitory sign on screen at startup

Posted in Apple Portable Computers

Symptoms

If you try to install a version of OS X (Snow Leopard or Lion) that was released before MacBook Air (Mid 2011), these symptoms may appear:

  • The computer begins to start up normally to a gray screen with the Apple logo, then switches to display a progress indicator (a spinning gear)