By Ivy / Last update December 13, 2021

Why clone HDD to external drive?

Cloning hard drives is becoming more and more common for the millions of Windows computer users globally. People are choosing to clone internal drives to external ones for a variety of different reasons. Below we will summarize the three main reasons why user clone their drives in Windows.

  • Clone internal hard drives to external hard drives. Some users prefer to backup their PC to external drive in order to protect their data before something bad happens or upgrading to Windows 11 without losing data, however, the backup will need to be restored before they will be able to access the data. Cloning the drive (rather than backing it up) solves this problem.

  • Clone a HDD to an external SSD to upgrade the disk. Cloning the system drive to an SSD helps users who are migrating their operating system and applications to new disk. All of the contents including the partition table, the MBR (master boot record), and the registry will be cloned to the target disk and as a result the user won’t have to reinstall their system.

  • Partition layout. Transferring a hard drive to an external hard drive to have an identical partition layout.

So, what tool do you need and how to copy a hard drive to an external hard drive? Please keep on reading.

The best way to clone a hard drive to a USB external drive

Windows doesn’t include a built-in cloning feature in its range of backup tools, therefore, we must turn to third-party cloning software. AOMEI Backupper Standard Edition is a free specialist disk cloning program that allows users to clone hard drives in Windows 10/8/7/XP/Vista and the latest system Windows 11 to external ones (such as SSDs, USBs, and external USB drives) in a few simple clicks. 

  • AOMEI Backupper enables users to clone smaller hard drive to larger drive to get more free space. You can even clone from larger hard drives to smaller ones using the Intelligent Clone function as long as the smaller drives are big enough for the cloned data.
  • It offers the Sector by Sector Clone function to help you make an exact copy of the source disk. Even blank or logically bad sectors will be cloned.
  • It provides you with the option to optimize your SSD during the cloning process, especially useful for when you clone your HDD to an external SSD drive.
  • It is compatible with all Windows PC operating systems, 32 bit or 64 bit.

AOMEI Backupper is free to download, and importantly it doesn’t include ads. Why not download it to have a try right now?

Download Freeware Win 11/10/8.1/8/7/XP
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Step by step guide: clone hard drive to external drive via freeware

To clone a laptop hard drive to an external hard drive, please connect the external drive to your computer using a USB to SATA adapter. If you have a desktop PC, you can directly install the external drive into one of the hard disk bays.

Please note that cloning will overwrite the target external drives data and files, so you should backup files that are important.

Step 1. Launch hard drive cloning software AOMEI Backupper Standard, then you will see its deep-blue screen. Click Clone and then select Disk Clone to start hard drive clone.

Clone HDD Disk

Step 2. Select the original HDD on your computer as the source disk. Then, click Next.

Choose HDD

Step 3. Select the external hard drive (USB drive, SSD, or other drive) as the destination disk. Then, click Next.

Choose External Drive

Step 4. Check the operation summary and click Start Clone to clone hard drive/SSD to external drive.

Clone HDD to External Drive

Step 5. Wait until the process complete 100% and click Finish. Then, replace your old hard drive and boot computer from the the cloned external drive, so you can make sure if it's bootable. Please be sure to change the boot sequence in the BIOS to make the external drive the priority.

Helpful Tips:

  • If you want to clone every sector on the hard drive, check the Sector by sector clone box. Make sure that the target disk is larger than or equal to the source disk, otherwise it will only clone the used part by default.

  • If you want to migrate operating system to SSD, then you should check the SSD Alignment box to improve your SSD’s performance.

  • To resize the partitions on the destination disk, you can click Edit Partitions and choose one of the features. The last two features are only available in the professional version,  if you want to use these features please upgrade to the Professional edition.

Edit Partitions

  • This version only supports cloning system disks MBR to MBR. If you need to clone a system GPT disk to GPT, GPT to MBR or MBR to GPT, we recommend that you upgrade to AOMEI Backupper Professional Edition.

  • To get the best performance from the cloned disk, you could consider cloning Windows 10 to NVMe SSD. It has the fastest transfer speed among SSDs.

Please be aware that the length of time the cloning process takes varies from drive to drive, if you have a large drive with lots of data the process may take slightly longer. 


AOMEI Backupper Standard Edition helps you clone HDD/SSD to external drive with just a few simple clicks, so you can get a working computer back easily and quickly in the event of a disaster. And this software also applies to clone external hard drive to internal, migrate Windows 10 to M.2 SSD, and clone SSD to larger SSD,  move hard drive to new computer in Windows 11, etc.

And it is crammed full of useful features and functions for managing your system. It enables you to backup your system, backup your PC to an external hard drive, clone boot drive to SSD, clone partitions in Windows 10, and more! Why wait? Why not try it now?