If a Partition Table that defines a logical drive within an extended partition becomes corrupt, Windows NT can no longer access that volume, or the volumes that follow it on the disk. Once the pointer to the next volume has been lost, Windows NT can no longer find out where the volumes start.
When an extended partition becomes corrupt, it might be possible to rebuild the information by using a sector editor or Partition Table editor.
For information about the organization of extended partitions, see "Logical Drives and Extended Partitions" in Chapter 17, "Disk and File System Basics." For information about ways to attempt to repair the extended partition, see the description of the DiskProbe utility in Chapter 22, "Disk, File System, and Backup Utilities."