By Emily / Last Updated April 22, 2022

"Can I clone a larger HDD to a smaller HDD?"

“Recently, I bought a new HDD of 250GB, planning to replace my old HDD (500GB in total, leaving 300GB free space) with Windows 10 installed. So I want to clone all the things into my new hard drive. Then I can boot computer from the new HDD as usual. But the problem is that the new HDD is smaller than the old one, so can I clone 500GB HDD to 250GB HDD? In other words, is it possible to clone to a smaller drive?”

Best software to clone HDD to smaller HDD in Windows PC

When it comes to cloning hard drive, you might just know how to clone hard drive to larger drive when you meet low disk space warning. But can you clone to a smaller drive? Yes, you can do that when you get proper and powerful disk cloning software.

Here AOMEI Partition Assistant Professional is highly recommended for Windows 11/10/8/7/XP/Vista users. This tool supports copying only used space from one disk to another, that is to say, as long as the used space of the source disk is smaller than the total available space of destination disk, you can clone a larger HDD to a smaller HDD or SSD drive.

Therefore, if you are experiencing the same situation as the user in the first section: the used space of the old hard drive is around 200GB and the new hard drive size is 250GB, you can clone the larger HDD to another smaller HDD or solid-state drive via AOMEI Partition Assistant.

Preparations before cloning a larger hard drive to a smaller hard drive

Prior to the cloning process, you have to make the following preparations:

✔Storage space of the smaller disk: ensure the smaller disk's storage space is at least the same or bigger than the used space of the source drive’s so that it can accommodate all the cloned sector data.

✔A complete backup of the smaller disk: all the contents on the smaller disk will be erased during the cloning process, so please make a complete backup in advance if there are something important.

✔Slim down the source disk: uninstall unnecessary applications, any temporary files, or redundant records no longer needed on the source disk to make it slimmer to easily fit the smaller HDD/SSD. Also, the storage space of the smaller disk is quite precious.

✔A method to connect the smaller disk: if the smaller disk isn't installed on the PC,  you can use either an adaptor or an external dock to attach it to your computer. 


✔A constant power supply: when cloning HDD to a smaller HDD on a laptop, connect your system to a reliable power source. Any abrupt power failure will disturb the cloning process and lead to data loss.

✔Boot mode support check: if you plan to clone MBR system disk to GPT or clone GPT system disk to MBR, you have to enter BIOS to change boot mode between BIOS and UEFI after clone, so that the Windows OS can boot from the cloned hard drive successfully. If you don’t want to change boot mode afterward, you can make the destination disk's partition style as same as the source disk's (MBR or GPT) in advance. Now Windows 11 has been released, if your system disk is an MBR disk, don't worry, AOMEI Partition Assistant also allows you to convert MBR and GPT without deleting volumes.

Simple steps to copy larger HDD to smaller HDD in Windows 11/10/8/7

now, you can download the Demo version and learn how to copy large HDD to smaller HDD in Windows computer via AOMEI Partition Assistant Pro.

Download Pro Demo Win 11/10/8.1/8/7/XP
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Step 1. Launch the hard drive cloning software. In the main interface, click “All Tools” and go to “Disk Clone Wizard”.

Disk Copy Wizard

Step 2. In this window, you have two copying methods. In order to copy a larger HDD to a smaller HDD, please choose “Clone Disk Quickly” which only copies the used space of the source disk. Then click “Next”.

Copy Disk Quickly

Step 3. Select the source disk you want to clone to the smaller disk. And click “Next”. Here we choose disk 1 (system disk and 931GB) as an example.

Select Source Disk

Step 4. Select the destination disk (350GB HDD, smaller than 931GB HDD) to contain all data on the source disk. Then a note on data loss on the target disk will appear, click “Yes” to close it and then click “Next” to continue.

Select Destination Disk

If you are cloning larger HDD to smaller SSD, you can tick the "Optimize the performance of SSD" to improve its reading and writing performance.

Step 5. Here, you can fit partitions or edit partitions on the target disk. The first option is unclickable since the target disk is smaller than the source disk.

Edit Disk

Step 6. Then you can see a note about how to boot from cloned disk. Click “Finish” after you read it.


Step 7. Back to the main interface, click “Apply” to perform the operation. Since it involves the system partition, it will be performed under PreOS mode, and a reboot is necessary.


Boot from cloned HDD: after you have cloned bigger hard drive to smaller HDD/SSD as above, you have to reboot your computer, long-press F1, F2, ESC or other specific keys to enter BIOS, access to Boot tab, and move the cloned smaller disk to the top of the boot order list. Then you can boot computer from destination disk.


With AOMEI Partition Assistant Professional, you can effortlessly clone HDD to smaller HDD and boot PC from cloned hard drive afterward. Besides, its “Migrate OS to SSD Wizard” also allows you to clone only Windows 10/8/7 partition to smaller HDD and SSD drive when necessary.

After cloning, you can format or wipe the old HDD for reuse. Moreover, this versatile disk manager software can even help you to allocate free space from one partition to another, split partition without losing data, extend NTFS system partition without rebooting computer, etc. Definitely worth your trying.