I have Windows 7 installed on the C: drive, which is shown as the "System, Boot, ... " drive in Disk Management. I also have another drive set as the D: drive, which has data on it. In the Boot section of the BIOS, the order under Hard Disk Drives is specified as the C: drive first, then the D: drive. This determines the order the system looks for the BootMgr, as I understand it.
Normally, Windows 7 boots without any problems. However, after I have installed a new program that requires a restart to complete, more often than not, I get "BootMgr is msissing". This is because, for some reason, the order of the drives in the Hard Disk Drives section has been switched round, and it is now trying to restart using the D: drive.
As I say, does anyone know what might cause the disks to be swapped?