I support people who use Vista, XP, Linux and Windows 7. My main work computer is Windows 7. My staff works on another Windows 7 computer. I want to build a third computer that will house Windows Small Business Server. I would like one of those machines to also run Vista, XP, and Linux as virtualized OS's so that I can run them as I need to support my clients. My preference would be to run those virtualized OS's on the SBS machine. My questions are: Will each OS working in a virtual box run the same as if they run native? Do I need to use a VMWare product or does Microsoft offer a good product that will allow me to do all of that? Should the base system I build have Linux as the primary and Vista, XP, and SBS run in virtualized state? Can I run more than one in a virtualized state at the same time? For example, if Linux is the base, can I run SBS all the time in a virtualized mode and invoke the others only when I need them?