As a follow-up on my question VMware Workstation 8: how to fake a bootable USB stick?
How can I mount a Windows folder as a virtual CD/DVD drive?
That way, I could mount the folder as a virtual CD/DVD drive on my host system, then use that CD/DVD drive in my guest VM to boot from.
Note: I know about SUBST, but that mounts the folder as a regular drive, not as a CD/DVD image.