I have a computer running Windows 7 Professional with a ASUS 8N Si deluxe motherboardthat I shut down the light for the hard drive went off but the green light stayed on. The computer will not boot up I tried using a repair disk with no success. I then tried reloading Windows 7 from the original disc.It gets to the point of "windows loading services" and stops. I now get the message BOOTMGR is missing. Any help will be appreciated.