You can do that. But I've never bothered. It would add an extra layer or two of cruft where it's not necessary. As well as use disk space unnecessarily when you

You can do that. But I've never bothered. It would add an extra layer or two of cruft where it's not necessary. As well as use disk space unnecessarily when you could better allocate 90% or more of your disk space to your main OS. Just pick one (Linux or Windows) and use that one as your base system. Make your guest disk as small as practical. My guest Win 7's C: drive is only about 40 gigs, which in a 12 TB system is pretty much just loose change.