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 ...

Windows 8 has the ability to create a bootable USB flash recovery drive that can be used to troubleshoot a Windows 8 computer that is unable to start. A recovery drive is the same as a startup repair ...

It is the first thing you need to fix the issue as stated above. For that, you need to run the virtual machine showing the error and go to the Devices > Install Guest ...

How to create a bootable VMware ESXi USB drive in Windows Your email has been sent Trying to get started with VMware's virtualization app but lack an optical drive on ...