The DISK_GEOMETRY structure describes the geometry of disk devices and media.
typedef struct _DISK_GEOMETRY { 
   LARGE_INTEGER  Cylinders; 
   MEDIA_TYPE  MediaType; 
   DWORD  TracksPerCylinder; 
   DWORD  SectorsPerTrack; 
   DWORD  BytesPerSector; 
} DISK_GEOMETRY ; 
 The DeviceIoControl function receives a DISK_GEOMETRY structure in response to an IOCTL_DISK_GET_DRIVE_GEOMETRY device input and output contol (IOCTL) operation. The DeviceIoControl function receives an array of DISK_GEOMETRY structures in response to an IOCTL_DISK_GET_MEDIA_TYPES device I/O operation.
  Windows NT: Requires version 3.1 or later.
  Windows: Unsupported.
  Windows CE: Unsupported.
  Header: Declared in winioctl.h.
Device Input and Output Overview, Device Input and Output Structures, DeviceIoControl, IOCTL_DISK_GET_DRIVE_GEOMETRY, IOCTL_DISK_GET_MEDIA_TYPES, MEDIA_TYPE