|Use assigned drive letter (default)|
The drive letter in the destination path is used exclusively to locate the backup target path.
This enables multiple backup drives to be used in rotation if Windows assigns the same drive letter for each drive.
|Use volume GUID path|
The unique volume identifier associated with the backup drive is saved in the backup definition file and used to locate the destination path.
This enables Windows to assign a different letter to the same drive and the new letter will be automatically chosen as the backup destination.
Note: If 'Use volume GUID path' is selected you must edit/re-save existing backup definitions to reflect the change in the XML file.