By Emily / Last Updated April 26, 2023

Why clone a hard drive to another hard drive?

Quite different from "copy and paste" which is mostly used to copy personal data such as videos, pictures, and documents. Cloning a hard drive is to copy all contents of a hard drive including the (boot) files, the partition tables, and the Master Boot Record to another hard drive. Afterward, both the source disk and the destination disk can be used directly. The OS and programs will load up and run as they work on the source disk.

You might need to clone a hard drive to another hard drive in Windows 10 for the following purposes:

• 1. Replace the failing hard drive with a good one
When your current old hard drive is about to fail, you can clone it to another new hard drive for replacement in case you lose important data during the hard drive crash.
• 2. Upgrade to a larger hard drive
When the current hard drive is too small to hold new data and usually pops out a “low disk space” warning, you can clone the hard drive to a larger hard drive for an upgrade.
• 3. Install the same Windows onto several computers
If you have a batch of computers with the same configuration to be installed, but don’t want to install them one by one, you can install only one first and then clone it to other main hard drives.

Although SSD is the mainstream on the disk market due to its better performance of data processing capacity, the traditional hard drive still has great market demand as a data disk not a system disk. A 2TB hard drive is cheaper than an SSD with the same capacity and normally, we suggest users don't use an SSD as a data disk because frequently erasing data on it is hurtful. 

Therefore, if you wish to do a hard drive upgrade or just wish to replace your old hard drive with a new one, cloning it is the best option.

What to prepare before cloning a hard drive?

To clone a hard drive to another hard drive smoothly, the following preparations will be all that you need to do.

1. Connect the secondary drive

To clone one disk to another, obviously, you will need the secondary hard drive, apart from the source disk. If you have a desktop computer, it will be easy to install both drives internally. If, however, if you are using a laptop with only one drive bay, you might need an external SATA-to-USB adapter, dock or enclosure to connect the second disk.

2. Check out the space of the destination drive

Generally speaking, the destination hard drive will need to be as large as, or larger than the used space of the source disk. If not, it is necessary to free up some space on your source disk to make the used space smaller than the total capacity of the destination drive.

3. Back up everything important on the destination disk

Since the cloning process will erase all data on the secondary disk, you will need to back up everything vital to another safe location beforehand.

4. Check the computer's boot mode

If you are looking to copy the system disk to another disk, you should pay attention to their respective partition tables (MBR or GPT) since you need to make a switch between UEFI and BIOS boot modes after cloning in order to boot your machine from the cloned disk.

5. Find a reliable and handy disk clone software

This is the most important point if you want to clone HDD to another HDD. An efficient cloning software can save your time and you from lots of troubles. It must have easy operation to make sure the whole process is foolproof.

Best clone software to clone hard drive to a larger/smaller hard drive

To clone hard disk to another hard disk, the easiest way is to use a professional hard drive clone tool. AOMEI Partition Assistant Professional will be a great choice. This software works well on all editions of Windows 11/10/8/7 and Windows XP/Vista (32-bit and 64-bit). It provides two different disk copying methods for different user requirements.

▶ 2 clone methods for different size disks

· Clone Disk Quickly: If your destination hard drive is smaller than the total size of the source hard drive but larger than the used space of the source hard drive, you can adopt this method, which will clone only used sectors from the hard disk to another disk.
· Sector-by-Sector Clone: If your source hard drive is encrypted with BitLocker and you are prepared to upgrade it to a larger hard drive, this method is perfect for your needs. It will clone both unused and used sectors to the target hard disk.

▶ Multiple cloning options

Apart from cloning an entire disk, it is even able to clone partition to another drive, or if you need, you can do an OS-only migration to use a familiar system environment on your new disk.

▶ Partition alignment

Partition alignment is specially designed to accelerate the reading and writing speed of both HDD and SSD. It refers to alignment between the 4K physical sector and cluster, as SSD and advanced formatted mechanical hard disk adopt the smallest 4K sector in the file system to save data. If the partition doesn’t start at the beginning of a physical sector, the physical sector and cluster will be shifted. Thus, reading and writing speed will slow down.

Tutorial: clone a hard drive to another hard drive on Windows PC

In this section, we will demonstrate how to clone a hard drive to another larger or smaller hard drive via AOMEI Partition Assistant Professional. This software comes with a free Demo version for users to download and have a try.

Download Pro Demo Win 11/10/8.1/8/7/XP
Secure Download

Step 1. Install and run AOMEI Partition Assistant Professional. Click “Clone Disk” in the right menu.

Copy Disk

Step 2. Select an appropriate method to copy the selected disk and click “Next”. If you are cloning a large hard disk to a smaller one, choose the first option, please.

Copy Disk Quickly

Step 3. Select a destination disk to contain all data from the source disk, and click “Next”.

If the destination disk is an SSD drive, you can tick “Optimize the performance of SSD” option during the process, which can help make 4K alignment on SSD partitions.

Select Destination Disk

Step 4. You can adjust partition size in this window if you choose “Clone Disk Quickly” above. After everything is done, hit on “Next” to continue.

Edit Disk

①Clone without resizing partitions: all partition will be cloned to the target disk as the original partition size. It is available when the target disk is large enough to hold all partitions on the source disk.
②Fit partitions to entire disk: all partitions will be cloned to the target disk and take up its full capacity according to the original partition size proportion.
③Edit partitions on this disk: you can change every partition size on the target disk as you need.

Step 5. A note will appear to tell you how to boot from the cloned disk. You can read it carefully, and then click “Finish”.


Step 6. Click “Apply” to commit the pending operation.


If you are cloning the system hard drive to another hard drive, to successfully boot from the destination hard drive and avoid the embarrassing moment that cloned SSD won’t boot, please do as below:

Step 1. Restart your computer, long press the "F2" key (perhaps other keys like DEL), and access the BIOS environment.

Step 2. Change the boot order and set the cloned hard drive as the first boot drive in BIOS.

Step 3. Press "Enter". Now you should boot the computer from the cloned hard disk successfully.

Further info: if you want to clone only the C drive and boot-related partitions to another hard drive, you can try its “Migrate OS to SSD/HDD Wizard”, which only transfers the OS partition to another hard drive and allows you to boot from it smoothly.

Migrate Os To Ssd



Now, you should know how to clone a hard drive to another hard drive in Windows 10/8/7 when it comes to transferring all data from the hard drive to the new hard drive. Apart from cloning the hard disk, the software can also allocate free space from one partition to another, recover deleted data/boot partition, convert system disk between MBR and GPT without deleting existing partitions, and convert dynamic to basic disk without losing data.

If you are cloning Windows Server hard drive, the AOMEI Partition Assistant Server can satisfy you best.