Download Internet Recovery Macbook Air Images. You can start the internet recovery reinstall process from either a shutdown mac, or by rebooting the mac. Internet recovery needs an internet connection to load the recovery tools from apple's servers.
The trick to getting into recovery mode will depend on the kind of mac you have. For macs with an intel processor, press and hold the command and r keys on your keyboard, then press the power button. It asks to cannot to a wireless network.
I connect to it type my password in correctly.
Internet recovery mode it shows the globe, asks for a wifi network, gets what it needs, starts actually entering the recovery app, shuts off. For macs with an intel processor, press and hold the command and r keys on your keyboard, then press the power button. Just as its name shows, you need to get your mac online. Some macbook and mac users have reported that they got stuck in recovery mode.