How to Migrate OS to Smaller SSD Securely | Step by Step

You will learn how to easily migrate OS to smaller SSD without Windows built-in software. This article will guide you through the entire process, from preparing for the migration to executing the transfer successfully. You will learn about essential tools, techniques, and tips to ensure a smooth transition.

By @Delia Last Updated October 23, 2024

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. My HDD has 600GB of data on it, so I can't fit all of it on the SSD. 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.”

– Reddit

Since HDD does not have a moving part, many users want to replace HDD with SSD to gain it. To be specific, SSD is much faster, durable, has lower weight, has no noise, and consumes less power. Many users will choose to migrate OS to smaller SSD. In fact, the key to migrating an HDD to a smaller SSD is to pick a handy system cloning tool.

Best software to transfer OS to smaller SSD successfully

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

But that is not the biggest problem. The thing is, Windows Backup and Restore 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 the restore system image to the new hard drive.

So it's not suggested to use a built-in tool for OS migration. The best way is to use a professional disk clone software like AOMEI Backupper Professional. It 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. 🔹It will be ok if the SSD disk is smaller since it uses the Intelligent Clone features, which only clones the used sectors of your system partition. 🔹It can help you further accelerate the reading and writing speed of the SSD disk as well as prolong its lifespan.

All the operations are based on an intuitive interface, so all the users can understand it easily and quickly. Please download it to have a try!

FREE Download Win 11/10/8.1/8/7/XP
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Preparations before migrating OS

  • Install the smaller SSD along with the HDD or prepare a SATA to USB cable or adapter for connecting if your computer only has one slot.
  • Be sure the smaller SSD can be detected by Windows on your computer.
  • Check the used space of the system partition. If it is larger than smaller SSD, you need to free up disk space. You can choose to use Disk Cleanup, manually delete some large files, or uninstall useless programs.
  • If the smaller SSD is not blank, please create a file backup for your important files.

How to migrate OS to smaller SSD step by step

With AOMEI Backupper installed, you can easily migrate OS to smaller SSD without reinstalling Windows, or even clone entire disk to smaller SSD as long as the capacity is sufficient to hold all the existing data.

Also, it supports cloning system disk between MBR or GPT, or from MBR to GPT and vice versa. Now I will show you how to perform the OS and data migration.

Steps to clone operating system to smaller SSD:

Step 1. Launch AOMEI Backupper Professional, and choose System Clone under Clone tab, or choose Disk Clone for a complete hard drive migration.

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

Step 3. Here comes the Operation Summary. Check the SSD Alignment box to boost the performance of your SSD disk and then click Start Clone to move OS to smaller SSD.

Notes:✎...
Make full use of disk space: By default, this feature will be checked if you are cloning OS to a larger drive. It's used to extend the size of the system partition by unallocated space.
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.

Tips on booting computer from the cloned SSD

  • Remove the 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 the 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.

FAQs about migrating OS to smaller SSD

Q1: How can I clone a larger disk to a smaller one?

A1: To clone a larger disk to a smaller one, you need specialized disk cloning software like AOMEI Backupper since Windows doesn't offer built-in tools for this.

Q2: Is it possible to clone one SSD to another?

A2: Yes, you can clone SSDs of different sizes. Just find a reliable cloning tool to assist you, and AOMEI Backupper is a great option for this task.

Q3: What should I do before cloning an HDD to an SSD?

A3: First, check the storage capacity of the new drive. Make sure it has enough space for all the data from your old HDD. For example, if your old HDD is 1TB, your new SSD should also be at least 1TB to avoid any space issues.

To wrap up

Unfortunately, the Windows backup tool doesn't let you transfer your OS to a smaller SSD. Instead, you'll need specialized cloning software for that. AOMEI Backupper can help, as it focuses on cloning just the operating system and uses the Intelligent Clone feature to copy only the used sectors. This makes it simpler to move your OS to a smaller SSD while ensuring a secure boot.

In addition, this powerful backup utility can help you create a system image backup in Windows and then restore it to a smaller SSD without any obstacle. You can even deploy system image to multiple computers using the technician or techplus edition. All in all, it is software worth trying, just pick the version you want.