I was trying to factory restore my old MacBook Air to pass on to a friend's teenage daughter for her GCSE's. I followed the instructions but when I got to erasing the startup disk there was no "Macintosh HD – data" in the sidebar and I ended up deleting "Macintosh HD" instead.
I have fairly average IT skills generally, but this is a very low point in my tech use!
I'm not sure I even really understand what I've done, but it seems bad? Will the computer ever be usable again?
Please help – really want to be able to pass the old computer on!