Hi there, On trying to return my macBook Air to factory settings, I went through disc utility and successfully erased the disc, but in my haste I think I quit disc utility without reinstating/reinstalling the OS. When I start up now it goes straight to black screen with the no entry sign. When I start up with cmd + R it goes to a spinning globe and asks me to choose network in a drop down. My internet does not show on the list despite being strong, and close to the router. I have tried starting up in safe mode with no result. I have reset, pressing down option but it will not start from the internal hard drive when I select that. I have reset pressing option ,plugged in an old Time machine backup from my other mac and selected that drive using the option method but it doesn't find the backup, but does intermittently have the grey folder with the question mark icon appear. I've reset PRAM et al but nothing works. Can anyone help please, I've run out of options and forums.