Can I clone Windows 10 to smaller SSD?
“I’m intending to upgrade my hard disk drive with Windows 10 installed to solid state
drive. As I’m unwilling to reinstall Windows 10 operating system, I decided to
migrate it by cloning. The problem is that the capacity of the HDD is 1TB and the
newly purchased SSD is 256GB. Is it possible to clone Windows 10 HDD to smaller
SSD?”
Great cloning software for Windows 10
Due to SSDs’ various merits like faster speed and high price, it is wiz to upgrade Windows HDD to smaller SSD. And you can avoid the trouble of reinstalling
Windows 10 by cloning HDD to smaller SSD. In fact, it is a rather simple task to clone Windows 10 disk to smaller, if the used space on the target disk is not larger than the capacity of the destination SSD and you employ proper disk cloning software.
AOMEI Partition Assistant Professional is just the right one; it offers two ways to copy disk: "Sector-by-Sector Clone"
and "Clone Disk Quickly". The latter one only copies used space on the source disk to destination one, allowing you to clone Windows 10 HDD to smaller SSD if the used space on the HDD is not larger than the capacity of SSD. What's more, if the destination disk is not large enough to hold all the data on the source HDD, it supports you to migrate only OS-related partitions (data partition not included) to smaller SSD as well via Migrate OS to SSD function.
AOMEI Partition Assistant Professional can not only work with Windows 10, but also with Windows 7/8/8.1, XP and Vista. If you need to clone Windows Server 2019/2016/2012 (R2)/2008 (R2) to SSD, you can employ AOMEI Partition Assistant Server.
5 Steps to clone Windows 10 to smaller SSD
To clone Windows 10 HDD to smaller SSD, connect the target SSD to your computer well
at first; then, install and run AOMEI Partition Assistant Professional.
✍ PS.: You can free download the demo version of AOMEI Partition Assistant Professional to have a try!
Step 1. In the main interface of AOMEI Partition Assistant
Professional, click “Disk Clone Wizard” and choose "Clone Disk Quickly". Then, click
“Next” button.

Step 2. Choose the Windows 10 HDD as the source disk and click
“Next”.

Step 3. Choose the smaller SSD as the destination disk. Then, hit
“Next”.

Step 4. Here you can adjust the partition size on the destination
SSD. As the SSD is smaller than HDD, the first option is greyed out.

A Note about how to boot from cloned disk (here is disk 2) will
prompt. Read and remember it.

Step 5. Go back to the main interface. Check the operation and click
“Apply” to execute it.

After moving Windows 10 HDD to smaller SSD by cloning, if you want to keep old HDD
and boot from SSD, you need to enter BIOS to change boot priority to SSD. If you clone GPT disk to smaller MBR SSD or MBR disk to GPT SSD, you also need to change boot mode between Legacy and UEFI.

Verdict
Under the help of AOMEI Partition Assistant, you can clone Windows 10 to smaller SSD easily and safely. In fact, it is more than disk cloning software for
Windows 10/8.1/8/7, XP and Vista. It enjoys many other functions like converting dynamic disk into basic without data loss, resizing system partition, creating Windows bootable USB drive, etc.