I've started getting this error when launching Windows 7 in Bootcamp. But Windows does start up. However when I try to run Windows from Lion I get the dreaded black-screen WINDOWS CAN'T START error. I did a Repair off my Windows Install DVD Then I deleted & then recreated a new 7 VM in Parallels. That worked, though I had to reactivate Windows. But now I'm back to Square One: MBR ERROR 3 in Bootcamp and Windows can't start in Parallels. Before I do it all over again, anyone got a better idea?