What Does a Disk Clone Do?

Disk Clone, also known as hard drive cloning, is a process to make an exact copy of the source disk to the target disk, including operating system, partition layout, drive letter, system reserved partition/EFI partition (for GPT disk), recovery partition, customized settings, installed programs, personal data and so on. You can perform a disk clone whether it's a system disk or data disk.

Clone hard drive

In addition to disc clone, there are other two cloning methods:

  • System Clone: it can be used for Windows operating system migration. It moves only system partition where Windows is installed and all the boot related partitions, like system reserved partition, recovery partition, EFI system partition (if exists) to the target disk.
  • Partition/Volume Clone: it can help you with data migration. It will copy all the data from selected partition/volume to destination partition, which is also a way that can be used to clone dynamic disk.

Disk Clone vs System Clone: Which One You Need

Both Disk Clone and System Clone features can help you migrate operating system to HDD/SSD while ensuring a secure boot. They also help to avoid reinstalling Windows and applications when your computer fails to boot. But which one do you need to use in different scenarios? Here are some suggestions about it.

▶ Four Disk Clone Scenarios | Need to Clone Hard Drive 

1. Hard Disk Upgrade: Hard disk that comes along with your desktop or laptop will run out of its space sooner or later. At this time, you need to upgrade hard disk for big capacity by cloning smaller disk to larger disk.
2. Make a Duplicate Disk: If all the data on the current system disk are important, it is necessary to do a full backup of the source disk by cloning hard drive. Thus, you can copy your data back quickly in the event of a disaster. Also, if the original hard drive is damaged, you could replace it with the cloned hard drive to enjoy exactly the same configuration as before.
3. Data Migration: It can help to quickly transfer all the data on a disk to another, such as the Windows operating system, installed programs, system settings, personal files, videos, etc. Meanwhile, a copy of original hard drive can greatly avoid data losses due to computer failure.
4. Data Recovery: In order to avoid secondary damage to the hard disk during data recovery, it is necessary to clone the disk and then restore what you want from the cloned disk.

▶ Two System Clone Scenarios | Need to Clone Only System Partition 

1. Transfer OS only: Cloning only system partition is a quick way to migrate OS to new hard drive or SSD. Also, it's a great idea to enjoy both excellent performance and big capacity by using SSD for OS and HDD for storage.
2. Smaller Target Disk: Sometimes, users want to clone hard drive to smaller SSD to get better performance, but the cloning may fail if you use sector-by-sector clone to clone all sectors of a hard drive. At this time, it's a wise choice to clone OS only.

Best Free Hard Drive Clone Software for Windows

As one of the best free disk cloning software for Windows 11/10/8.1/8/7/XP/Vista, AOMEI Backupper owns the following remarkable features:

◑ It provides 3 clone types: Disk Clone, System Clone (supported by Professional edition), Partition Clone.

◑ It allows you to clone hard drive to another HDD or SSD without breaking off the running operating system (called "Live Disk Cloning"). That is to say, it can run disk to disk clone while you are working on the computer.

◑ By default, this disk clone software just clones the existing data (the used sectors) on the disk. If you would like to clone all the sectors on the source disk, whether it is used or not, please try the "Sector by sector clone" option.

◑ If your target drive is an SSD, you could use "SSD Alignment" to accelerate the reading and writing speed of SSD. By the way, this feature can still extend SSDs' lifespan.

This hard drive cloning tool also helps you make bootable media when the Windows refuses to boot or you don't want to load operating system while cloning. Of course, it will be OK if you don't have any media. You can simply add recovery environment entry using AOMEI Backupper Recovery Environment. 

How to Easily Clone a Hard Drive with AOMEI Backupper

AOMEI Backupper allows you to clone hard drive with different size in Windows 11/10/8/7/XP/Vista, including:

But there is a precondition. That is the space on the destination disk is able to accommodate all the valid data on the source disk. If there is not enough space on the destination disk, AOMEI Backupper will calculate and inform you that: The selected disk is too small, required the disk size at least: ** GB when you select the disk as the destination.

Then, let's see the detailed steps to clone disk as follows (take cloning hard drive to SSD as an example). First of all, please download this free tool, install and launch it.

Download Freeware Win 11/10/8.1/8/7/XP
Secure Download

★Before cloning:
◐ Please note all data on the destination disk will be overwritten or deleted after the cloning is finished, so backup important files ahead of time.
◐ If you want to clone hard drive to external drive, please connect it to your PC beforehand. And if it's not initialized, please initialize it in Disk Management before cloning.

Graphic Guide:

This graphic guide will show more details about how to perform disk to disk clone. You could follow it to have a try:

Step 1. To clone a hard drive, select "Disk Clone" option under the "Clone" tab.

Disk Clone

Step 2. Select the source disk (Disk0) which you want to clone, and then click "Next".

Select Source Disk

Step 3. Select another drive or SSD as destination disk (Disk2) where you want to clone source disk to, and then click "Next". 

Select Destination Disk

If the destination disk is not empty, you will be prompted the destination disk will be overwritten or deleted. Click "OK" to continue as you have made a backup before.

Backup Data First

Step 4. As you are cloning hard drive to SSD, it is recommended to check the box before "SSD Alignment" to optimize the performance and lifespan for SSD. Confirm the settings, and then click "Start Clone" to clone HDD to SSD safely.

Start Clone

★Helpful tips
✍ "Sector by sector clone": clone all sectors on source disk to destination disk, no matter they are used or not. If you clone large hard drive to smaller SSD, DO NOT choose this option, or the cloning process will fail.
✍ "Edit Partitions": make the target drive show full capacity when cloning disk to a larger one. The option "Add unused space to all partitions" and "Manually adjust partition size" are available in advanced versions.

Step 5. Click "Finish" when all the disk cloning operations have been done.


In fact, disk clone is also called "Disk to Disk (Disk2Disk)". There is a similar function - disk imaging, which can store all the data on a disk to an image file. That is the so-called "Disk to Image (Disk2Image)". AOMEI Backupper can realize Disk2Disk as well as Disk2Image. It can backup your disk to an image file so that you can restore your disk in the future.

  • In general, the disk that contains the current operating system cannot be used as the destination disk. To complete that for special purpose, you can create a bootable disc and perform cloning in WinPE mode.
  • If the destination disk is a dynamic disk, you have to convert it to basic disk without losing data first. Or you can turn to "System Clone" (supported by AOMEI Backupper Professional) and "Partition Clone" feature for help.
  • If you have both SSD and HDD disk, you could consider using SSD for OS and HDD for storage. It makes full use of the advantages of SSD and HDD.
  • The Standard edition only supports cloning MBR system disk to MBR disk. If you want to clone a system disk from MBR to GPT, GPT to MBR, or GPT to GPT, you could consider upgrading to AOMEI Backupper Professional.
  • To clone disks on any computer, you may use AOMEI Backupper Technician or Technician Plus to create portable version

Video Guide:

This is a quick navigation to the entire process of hard drive clone. Compared with the graphic guide, it is more intuitive and easy to understand. You can check it before cloning.

Boot from Cloned Hard Drive 

If you're cloning the disk with operating system installed, it is suggested to restart your computer and continuously press a specific key (usually F2, F8, F12, Del) to enter BIOS Setup -> Boot, then set the cloned disk as first boot device in BIOS or replace the old hard drive with the new drive directly to boot from the cloned drive. 

Change Boot Order BIOS