NT signature

The NT signature is a record that is kept in the MBR. It uniquely identifies the disk for the operating system.

When recovering a disk containing a system volume, you can choose what to do with the NT signature of the target disk. Specify any of the following parameters:

• Select automatically

  The software will keep the NT signature of the target disk if it is the same as the NT signature stored in the backup. (In other words, if you recover the disk to the same disk that was backed up.) Otherwise, the software will generate a new NT signature for the target disk.

  This is the default selection recommended in most cases. Use the following settings only if you absolutely need to.

• Create new

  Acronis Backup will generate a new NT signature for the target hard disk.

• Recover from backup

  Acronis Backup will replace the NT signature of the target hard disk with one from the disk backup.

  Note: You should be absolutely sure that none of the existing disks on this machine has the same NT signature. Otherwise, the operating system runs from the first disk at the startup; discovers the same signature on the second one, automatically generates a new unique NT signature and assigns it to the second disk. As a result, all the volumes on the second disk will lose their letters, all paths will be invalid on the disk, and programs won't find their files. The operating system on that disk will be unbootable.

  Recovering the disk signature may be desirable due to the following reasons:

  • Acronis Backup schedules tasks using the signature of the source hard disk. If you recover the same disk signature, you don't need to re-create or edit the tasks created previously.
  • Some installed applications use disk signature for licensing and other purposes.
  • This enables you to keep all the Windows Restore Points on the recovered disk.
  • To recover VSS snapshots used by Windows Vista's "Previous Versions" feature.
• Keep existing

  The program will leave the NT signature of the target hard disk untouched.