Ok so I'm trying to reistall windows vista on my computer after trying to upgrade to windows 7 but failing. I can sucessfully installed it but everytime I restart my machine it keeps telling my Bootmgr missing. I've reistalled it 3 times already and even formatted the hard drive c too and that message keeps coming up and I can't get windows to load up. The werid thing is when i have the insttall disc in the tray it boots up...pleeeas help. This is the reason why I am trying to reistall vista again after I first got this message sfter installing win7. what can i do? what is bootmgr?