When you login to your IDrive account for the first time on a new QNAP machine, it allows you to either restore your previous computer's backup archive on your new computer or create a new location with the new computer name. 
You can select the Adopt/Link to an existing location/computer option to restore the previous computer's backup archive, thus avoiding time consuming initial backup. If you do not wish to adopt your previous backups on the new machine, you can click Proceed to create new location with this computer name, when prompted to select location/computer for backup.

To adopt your backup archive,

1. Install QNAP backup app in your NAS machine and login to the QNAP Backup App.
2. Click Adopt/Link to an existing location/computer when prompted to select location/computer for backup. A list of locations/computers linked to your account appears.
   
   
   
   
3. Select the desired computer/location from the list and click Adopt/Link Selected Location to restore your previous backups.
   
   

Note: This feature is only available for certain accounts.