Not all HD content is degraded, only specific protected content. At the moment this is only Blu-ray + HD discs, Some TV cable cards (I believe). In theory DRM'd downloaded WMV's could also use it but they currently don't. All other HD files, including your WMVs mentioned, are not affected, and do not have to have an encrypted path / downgraded resolution. That is not to say you may still have issues playing them, but in this case they would probably be driver related, not content protection related. For the second question, yes I've dual booted. I used an OEM version of home premium, and on installation it gave me the option of installing onto a different partition / disk.