How to Backup an External Hard Drive to Another External Hard Drive For those who would like to learn how to [**back up an external hard drive**](https://notchox.com/resources/backup-external-hard-drive/) to another external hard drive, begin by attaching both hard drives to the computer. In File Explorer (for Windows users) or Finder (Mac users), find the first hard drive and select the files and folders to be backed up. Then right-click, select “Copy,” and paste them into a properly labeled folder on the second drive. Make sure there is enough available space on the target device. For a massive backup, do so in several sessions and ensure that all important files are opened successfully. Disconnect the backup drive when it is not used to avoid accidental deletion or damage to both drives from malware. Notchox informs about the data recovery process.