There are several ways to affect a restore.
If your computer can boot and run directly from the backup hard disk, you can simply copy it back to the original. When booting and running from the backup, it will take on the identity of the original drive. Consequently, the process of restoring the original drive would be the same as the process used to create the backup. For example, while booting and running from the backup hard disk, you would use Casper to copy the backup hard disk to the original hard disk.
Booting from the backup hard disk requires you to have the hard disk attached via a supported external interface or installed internally. If the backup hard disk is installed internally or attached via eSATA, you can boot and run the computer directly from the backup hard disk. If the backup hard disk is attached via USB or Firewire, you will need to physically remove the hard disk from its external housing and install it as an internal hard disk in order to boot from it.
As an alternative to booting and running the computer from the backup hard disk, the Casper Startup Disk can be used to boot the computer and copy the backup hard disk to the original hard disk. For example, with the external backup hard disk attached to the system, you can boot the computer via the Casper Startup Disk (CD) and then copy the external backup hard disk to your computer's internal hard disk.
The Casper Startup Disk (CD) is available as an optional component for Casper that must be purchased separately or obtained as part of the Casper Value Pack. It's available online at http://shop.fssdev.com and distributed as a compressed ISO file. Instructions for creating the CD are available in the Casper User Guide. See "Creating and Using the Casper Startup Disk."
Once you have created the startup disk, you would follow this general procedure to perform the restore:
Attach and power on the external backup drive. (NOTE: This must be done before booting from the CD.)
Boot the computer from the Casper Startup CD. The boot process may take several minutes to complete. When finished, you will see the normal Casper console menu (e.g., Copy Drive, Create Drive, Remove Drive, Explore, Exit).
Click Copy Drive, and reverse the procedure you used to complete the original backup – e.g., select your external drive as the source and the internal drive as the destination.
NOTE: When the system is booting and running from the Casper Startup Disk, the drive letters and/or disk unit numbers assigned to the hard disks may be different than when the system is booted normally. EXERCISE CAUTION WHEN SELECTING THE DESTINATION DISK. For example, while the computer's internal hard disk will likely be identified as disk 1, this may not be the case. If you are unsure of the drive letters assigned to your external vs. internal drive, click Explore. Casper Explorer will show your internal and external hard disk and the drive letter(s) associated with each. Use the model number listed under the Description column and/or size to identify the disks.