Eventually you will see a screen where you can pick a Wi-Fi network.

To get there, power the computer on, hit the power button and very soon after, hold the option key. Luckily there is another way to connect, via apple’s boot menu. If instead your MacBook lets you select a Wi-Fi network during this process, you’re in the clear and can skip the next paragraph. This tends to be because the Mac assumes it is already connected to Wi-Fi (when its not) and gives an error after it fails to connect to apple servers. There is a bit of a catch: if you do this straight away, there is a good chance that the Mac will get stuck here and throw up an error – error -3001F in my personal experience. The way forward is to use the built-in “internet recovery” which, on startup, can be triggered via pressing “cmd + R”. It may seem like you just bricked your MacBook, but luckily there is a remedy. If you’re anything like me, you will (or already have) accidentally wiped your Macbook’s ssd.

How to clear a macbook hard drive