By Dervish / Last Updated March 3, 2022

Why we need to clone a computer system?

How to clone a computer system? This may be a question when we need to replace a new disk. In ordinary life or work, we choose to clone a computer operating system for the following reasons:

The aging of computer hardware such as motherboards, graphics cards and other devices makes you no longer able to use it. But you are very satisfied with the current operating system, so when you buy a new computer, you plan to clone the old system to the new computer for use.
If you want to upgrade HDD to SSD to improve the performance of the computer, you can clone the Windows system to SSD without reinstalling.
Clone the system to an external hard drive for backup.

How to clone a computer system easily and safely

AOMEI Partition Assistant Professional (highly recommend for Windows 11/10/8/7/Vista/XP users) is a powerful third-party cloning software, it is one of the best cloning software on the market. 

It can clone all data of the old hard drive (including the system) to the new hard drive without data loss, and can successfully boot from the new hard drive. If you plan to clone a Windows system,  you can try to Migrate OS to SSD, because it only moves system-related data to the new disk, leaving other data in the source disk.

Please download the Demo version to see how to clone system in Windows via AOMEI Partition Assistant Professional.

Download Demo Win 11/10/8.1/8/7/XP
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✎ What to do before cloning computer system:
1. If your hard drive is brand new and unused, please initialize it in advance.
2. Connect the new hard drive to your computer and make sure it is detected successfully.

>>If you are using a desktop, you need to open the case and hook up the new disk to motherboard.
>>If your computer is a laptop, you have to connect new disk via USB port and the new disk should be put in a USB adapter.

Step 1. Free download this computer operating system clone software, then install and open it. In the operation bar on the left, in "All Tools", select "Disk Clone Wizard".

Step 2. Here, choose a suitable method based on the differences mentioned above (choose the first method as an example).

Clone Disk Quickly: refers to fast cloning of used sectors to the target disk or partition, allowing the capacity of the target disk to be smaller than the capacity of the original disk.
Sector-by-Sector Clone: refers to clone all sectors of the original disk to the new disk, so the capacity of the new disk is required to be equal to or greater than the original disk.

Step 3. Select the disk where the operating system is located here (take Disk 1 as an example).

Step 4. Here, select the target disk where you plan to clone the operating system (take Disk 2 as an example). If your target disk is an SSD, you can check "Optimize the performance of SSD". The purpose of this is to improve the SSD read and write speed.

Step 5. In this step, you can adjust the size of the target disk partition. If it is cloned to a smaller hard drive, then the first item is not selectable.

Step 6. You can preview all operations this time in this window. Click "Apply" to submit for execution.

This is the whole process of how to clone a computer system. If you don't know how to make it run, please continue to read.

How to boot from the new disk after cloning

After you clone a computer system to a hard drive, you need to put the new disk back and change the boot sequence in the BIOS menu to boot Windows 11/10/8/7 from the new hard drive.

1. Keep pressing F2, F3, F4, F5, ESC or other keys to enter the BIOS menu when the computer starts.

2.  In the BIOS menu, choose “Enter setup”

3. Choose “Change boot order” in the “setup” utility.

4. To make the cloned hard drive take precedence over other hard drives, move it to the first one.

5. Save the changes and exit the BIOS setup utility. The computer will restart.

What to do if it does not start after cloning?

If you want to use the newly cloned hard drive in the same computer, you should pay attention to whether the hard drive is an MBR hard drive, because you need to set the boot mode to Legacy/CSM boot mode. If Windows 10 is cloned to a GPT hard drive, the motherboard not only needs to support EFI/UEFI, but also set the boot mode to EFI/UEFI boot mode. Otherwise, the computer cannot start from the drive

Finally, if you clone the computer system to a new computer with different hardware, your new computer may not start normally. Because when you first install the system on the first computer, Windows will set itself according to the motherboard device, chipset, CPU, etc. of the PC. For the second PC when the operating system is moved, Windows may not run successfully due to various hardware differences.

Fortunately, Universal Restore allows you to restore the operating system to a computer with different hardware. Therefore, you can immediately restore the operating system and deploy the same operating system to multiple computers in the event of a hardware failure.​