I've just discovered that the VM on Virtual Box (running a Windows 7) didn't work. It needs special drivers installed to boot from the SSD. I've reinstalled VB, but now that the optical is USB, there's no way the damn thing sees it as a boot device to run the Windows install disc. I've configured it to "get" the port, and have installed the extension pack which adds USB compatibility. VB seems to see the "generic USB" and the disc spins, but it says it can't read the bootable.
If mounted on OSX, the disc shows perfectly all its contents. Moreover this is the very same disc I used to install W7 over VB in this very same MB before the upgrades.
I've even tried a different external DVD-RW unit, with the same lack of success. Any suggestions? I've considered trying to make a bootable pen or SD card with W7, but I can't on OSX, nor know how to extract a CD/DVD to create an .iso or other image into a HDD on OSX. Not that I think that would work, but perhaps worth trying.
I still may try Parallels or the other VM software, but for my purposes, VB worked very well and it's free