MBR info

from Wikipedia

Note, when having various TDSS and other rootkits whcih invade the MBR, diskpart cannot see drives (lis dis in CL).

Though it is possible to manipulate the bytes in the MBR sector directly using various disk editors, there are tools to write fixed sets of functioning code to the MBR. Since MS-DOS 5.0, the DOS-mode program fdisk has included the (undocumented, but widely used) switch /mbr, which will rewrite the MBR code. Under Windows 2000 or later, the Recovery Console can be used to write new MBR code to a hard disk using its fixmbr command. Under Windows Vista and Windows 7, the Recovery Environment can be used to write new MBR code to a hard disk by clicking on Command Prompt and typing bootrec /FixMbr. Some third-party utilities may also be used for directly editing the contents of partition tables (without requiring any knowledge of hexadecimal or disk/sector editors).