Busch looks like you have a system issue with your WMI Class. Here is a good article on technet about troubleshooting WMI Providers and Classes that should help you out.
If you’ve verified that you ran the command as a local Administrator, and it isn’t retrieving Win32_OperatingSystem when you’re in a local console window (which says “Administrator” in the title bar), then I’m gonna go with “borked system.” I’m a little hesitant to recommend a fix because I’m not at all familiar with SBS or any weirdness it may have.