Problem: A friend have a MacOS computer. The hard disk inside started ticking (probably stuck heads). Hard disk was unusable.
He bought an empty hard disk but when he replaced it, it was giving a folder with a question mark icon (missing OS I suppose).
He brought me the empty hard disk asking me to reinstall OS on it. I never used Apple products.
I usually do this kind of stuff for windows and I prepare a bootable usb drive with the Windows OS on it. Plug the usb in the computer and install windows.
How to install MacOS on a clean & virgin hard drive so he can put the hard disk back on the Macbook and use it?
tl;dr: I need from Windows to install from an ISO or whatever, the Snow Leopard OS on a clean and new Hard disk, and put it back on a mac computer with the OS on it so it can start.
EDIT IT IS AN iMac 27'' from 2009 and it was mounting Snow Leopard 10.6