That's beside the point. I want to ask whether there is any use in installing a newer version of DX over DX8, knowing that it is either "partially supported" (in the sense that only the DX8-compatible subset of the newer version is supported in terms of "graphics ability") or "not supported at all" (in the sense that the newer version is newer than DX8).
I also want to know whether there might be some kind of loss when it comes to doing such an installation on the guest OS (my Windows XP VM has DX9 installed, for example, even though the VM can only support DX8), and if so, whether there is a way to rollback to a "safe version".