I'm not quite sure if this is the correct place for this - if not, please feel free to move it.
I recently had an issue with my bootmgr file missing - or probably more accurately, with Windows not being able to detect it. More about that issue (which has been resolved), can be seen in this topic:
So, everything seemed to be solved. Then, when I rebooted, I got the same missing bootmgr message again. On a whim, I did a reboot and entered the BIOS. Sure enough, the first boot device was NOT my system drive. It was the USB card reader on my printer. I corrected that, rebooted, and all was well until the next reboot, when yet another drive was incorrectly listed as the first boot device.
I have no idea why the BIOS settings would change with each startup. Further, I've always been under the impression that the system will look at the first boot device listed, and if there is no OS there, it will move on to the next, and so on, until it finds the OS.
As a temporary fix, I tried disabling all boot devices except the first boot device, specifying my system drive as the boot device. That did not work - it still changed to a randomly selected drive and attempted to boot from it.
Edited by MelissaPleases, 26 August 2014 - 07:49 PM.