By Delia / Last update July 19, 2021

User case: How to move OS to smaller SSD?

"So I have a 1TB Seagate HDD, and recently bought a 240GB Kingston SSD. I am running windows 7 from the HDD but want to move it to my SSD. I have seen videos where people use tools to clone the HDD to the SSD, but my HDD has 600GB of data on it, so I can't fit all of it on the SSD.

So what I would like to do is move my windows installation to the SSD and then move some programs over as well. I'm really trying to get my head around what I need to do and how I would do this. Any help is appreciated."

Why migrate OS to smaller SSD?

As we all-known, SSD (Solid-state Drive) has significant advantages than traditional hard drive, thus many users want to replace HDD with SSD to gain it. To be specific , SSD is much more faster, durable, lower weight, no noise, and consume less power. 

However, at the same price., most SSDs hold smaller capacity than HDDs, so users cannot move everything from HDD to SSD due to insufficient disk space. In this case, many users will choose to migrate OS only to smaller SSD and then use HDD for storage.

Best way to transfer OS to smaller SSD

Windows backup utility is the first option for most users to migrate operating system by backup and restore method. To complete the process, you need to create a system image backup with Backup and Restore and then restore system image to new SSD. Between these two processes, you need another storage device to store the backup image. In sum, you need to move system image twice, time-consuiming and tedious.

Create a system image Windows 10

But that is not the biggested problem. It does not allow you to restore system to partition layouts that smaller than the original disk. If you do so, you will receive the system image restore failed error. To learn more, see restore system image to new hard drive.

System Image Restore Failed

Thus, it's not suggested to use built-in tool for OS migration. The best way is  using a professional disk cloning software like AOMEI Backupper Professional, which can put everything in place in one step and ensure the cloned SSD is bootable.

 To transfer OS, you will use its System Clone feature, which will include the operating system, boot partition(s) like system reserved partition, personal data, installed programs, etc. And it will be ok if the SSD disk is smaller, because this software only clones the used sectors of your system partition with Intelligent Clone feature. And  it can help you further accelerate the reading and writing speed of SSD disk as well as prolong its lifespan with SSD Alignment feature.

Download it to have a try if you want an easier way! Note that the Clone feature in the free trial version can only be demonstrated, please upgrade to the full version of AOMEI Backupper Professional and enjoy this feature.

Download Free Trial Win 10/8.1/8/7/XP
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How to easily migrate OS to smaller SSD without reinstalling Windows?

Before you start to move OS to smaller SSD, please make some preparations as follow:

  • prepare a way to connect SSD disk. If your computer only has one slot or it's a laptop, you need a SATA to USB cable or adapter.
  • Be sure the smaller SSD can be detected in your computer.
  • Check the used disk space on both HDD and SSD. If there is not enough space, you need to free up disk space by Disk Cleanup or manually delete some large files or uninstall useless program.
  • Create a file backup for your important files if the target SSD disk does not have enough space to hold all the data on the system partition.

Then, continue to see below and learn the detailed steps:

1. Launch AOMEI Backupper Professional, and choose System Clone under Clone tab.

System Clone

2. Choose the smaller SSD as the Destination Partition and click Next. The system and system related partitions are selected by default.

Choose Destination Partition

3. Here comes the Operation Summary. Check SSD Alignment box to boost performance of your SSD disk nd then click Start Clone.

System Clone SSD Alignment Checked

Note: Sector by sector clone means cloning every part (both used and unused part) of a disk to SSD. You can ignore this option in this situation, otherwise this operation will fail due to insufficient disk space.

Tip on boot computer from the cloned SSD: You need to remove previous hard drive and install the new SSD on your computer to let Windows OS boot from SSD. If it does not boot, please change boot settings in BIOS and try to boot from it again.

Just within 3 simple steps, you are able to migrate OS to smaller SSD successfully and ensure your computer can boot from it. Actually, if your SSD is large enough to contain everything on the HDD, you can clone entire disk to SSD with Disk Clone feature in this software. 

Your Turn

If you need an easy but safe way to migrate OS to smaller SSD, SSD cloning software AOMEI Backupper Professional can be a great option. It supports 3 cloning solutions, thus you can clone partition, system or disk per your needs and replace hard drive with SSD easily and quickly. 

If the SSD disk is smaller, you can choose to clone only used sectors with Intelligent Clone feature. If the SSD disk is smaller, you can clone all sectors with Sector by sector clone and adjust partition of target disk to avoid unallocated space after cloning. In addition, you can SSD Alignment feature to improve performance of SSD disk whether it's larger or smaller.

In addition, this powerful backup utility can help you create system image backup in Windows and then restore it to smaller SSD without any obstacle. Also, you are allowed to backup hard drive without booting Windows, create continous data protection, etc. Other helpful features like create bootable media, selective file restore, universal restore, and so on are embedded in this software. All in all, it is a software worth trying, and it has 30-day free trial.