The "Bootable" legacy ISO you've used is in fact not bootable, it relies on CDROM emulation provided by BIOS. VMs don't usually do this sort of emulation. If you set the guest OS to something like ...
When something goes wrong with your Mac, it's a boon to have a separate, external drive that you can work from — but Apple no longer makes that easy. Here's how to do it. The short answer to how you ...