How to Clone Windows to Smaller SSD | Securely Boot

Are you looking for the solution to clone Windows OS to a smaller SSD? You are in the right place. This blog elaborates on how to clone Windows 11/10 to a smaller disk with a robust OS migration, EaseUS Disk Copy. Whether you are a beginner or an advanced user, you can do it easily with simple clicks.

❓Question: Can I Clone Windows to a Smaller SSD?

It is a common dilemma that many users want to upgrade to a faster SSD but worry about losing data while cloning the hard drive to a smaller SSD. The good news is that you can migrate OS to a smaller SSD as long as its storage is smaller than the overall capacity of the new SSD.

In this guide, we'll walk you through the entire process, including how to check storage space, clean up unnecessary files, clone your system correctly, and boot from the cloned SSD, ensuring a smooth transition to your new SSD

What to Prepare Before Cloning Windows to a Smaller SSD

Before cloning, you should make some preparations to ensure a smooth process. Here's how to prepare properly:

1. ✅Check Your Current Disk Usage

• Open File Explorer > Right-click C drive > Properties.
• If "Used space" exceeds your SSD's capacity, you can release space by deleting temporary files, uninstalling unused programs, or moving large files to an external drive.

2. ✅Shrink the Windows Partition (optional)

If your data fits, but the partition is too large:

• Open Disk Management.
• Right-click C: drive > Shrink Volume.
• Enter the amount to shrink (leave enough free space for future updates).

3. ✅Download a Reliable Disk Cloning Tool

Since Windows lacks built-in cloning for smaller drives, you must make use of a third-party tool, and EaseUS Disk Copy is one of the most popular choices because it will automatically adjust partitions to fit smaller SSDs, support UEFI/GPT/MBR boot modes, and ensure 4K alignment for SSD performance. It is compatible with various HDDs/SSDs, and allows you to move the OS to SSD without any boot issues. Download and get ready for the cloning process.

4. ✅Connect SSD to the Computer Properly

It is very important to ensure that the device recognizes the new SSD. If your computer has only one disk bay, connect it with an adapter or USB-to-SATA cable. If your computer contains an extra disk slot, you can install the SSD directly into the computer.

Share this guide on your Twitter/Instagram to help your fans and friends migrate Windows OS to a smaller SSD smoothly.

How to Clone Windows 11/10 to a Smaller SSD

With all the preparations done, now that your system is ready, follow these detailed steps to copy your Windows OS to the smaller SSD smoothly.

📖Preparations before cloning start:

• A screwdriver, a Power Splitter Adapter Cable, a SATA cable, or a USB to SATA adapter. 
• Make sure the target HDD/SSD has an equal or bigger capacity than the used space of the old system capacity.
• Check whether the style of the new disk is the same as that of the old disk. If not, Initialize a new HDD/SSD to MBR or GPT.
• Download a Disk Cloning Tool – EaseUS Disk Copy

Step 1. Launch EaseUS Disk Copy, under the "System Mode", select the new second HDD/SSD as the target disk.

Step 2. Adjust the target disk layout to fit into the new disk. Tick the "Check the option if the target is SSD" option to put your SSD in its best performance.

• Autofit the disk: makes some changes by default on the destination disk layout to work at its best status.
• Copy as the source: does not change anything on the destination disk, and the layout is the same as the source disk.
• Edit disk layout: allows you to resize/move partition layout on this destination disk manually.

Step 3. Click the Proceed button, and a message will appear to warn you that data will be lost. Please confirm this message by clicking Continue.

Step 4. Wait for the process to complete, and you can check the integrity of the cloned hard drive and view if the OS has been migrated to it.

Prior Notice:

• The "Sector by sector copy" asks the size of your destination disk to be at least equal to or larger than that of the source disk. Leave this feature unchecked if you wish to clone a larger hard disk to a smaller hard disk.
• All data on the destination disk will be completely erased, so take care.

Step 1. To start copying/cloning an entire disk to another, choose this disk as the source disk under "Disk Mode" and click "Next".

Step 2. Choose the other disk as the destination disk.

Step 3. Check the disk layout of the two disks. You can manage the disk layout of the destination disk by selecting "Autofit the disk", "Copy as the source" or "Edit disk layout". 

• "Autofit the disk" makes some changes by default on the destination disk layout so that it can work at its best status.
• "Copy as the source"does not change anything on destination disk and the layout is the same as source disk.
• "Edit disk layout" allows you to manually resize/move partition layout on this destination disk.

Tick the "Check the option if the target is SSD" option to put your SSD in its best performance.

A message now appears, warning you that data will be lost. Please confirm this message by clicking "OK" and then click "Next".

Step 4. Click "Proceed" to officially execute the task.

How to Make the Smaller SSD Bootable After Cloning

After cloning, you can now swap to the new cloned SSD and run Windows on the new disk. Here are the steps:

As for the old hard drive, you can use it as a secondary storage drive if your computer has an extra disk bay.

However, according to many users' feedback, the unbootable problem is always encountered after cloning, which is very frustrating. Here are some solutions you can try to make your system botable.

1️⃣. Change Boot Order in BIOS/UEFI

• Restart PC and enter BIOS (F2/DEL key).
• Set the new SSD as the first boot device.

2️⃣. Verify Disk Partition Style (GPT/MBR)

• Open Disk Management and check if the SSD matches the source disk's style (GPT for UEFI, MBR for Legacy).
• If not, change GPT/MBR in Disk Management before cloning.

Share this guide on your Twitter/Instagram to help your fans and friends migrate Windows OS to a smaller SSD smoothly.

Final Verdict

Cloning Windows to a smaller SSD is 100% possible if you ensure that the used data is smaller than the SSD's capacity. With the help of EaseUS Disk Copy, the process will be much easier, and save you the trouble of manipulating complex steps.

By following this guide, you'll avoid failed cloning, unbootable drives, and SSD performance issues. Getting your faster SSD up and running in no time.

FAQs About Cloning Windows to Smaller SSD

Why is my SSD capacity smaller after cloning?

After cloning, your SSD may show a smaller capacity due to partition alignment issues or leftover recovery partitions from the old drive. The cloning process usually copies partitions exactly, including unused space. You can use Disk Management to check for unallocated space or resize partitions. Also, some SSDs reserve extra space for over-provisioning, which isn't user-accessible but improves performance and longevity.

How to clone HDD to SSD different sizes?

To clone HDD to SSD of different sizes, you need to ensure that the used space of the HDD must be smaller than the overall capacity of the SSD, then follow the normal process to clone HDD to SSD. If the used space is larger than the SSD, you can remove some unnecessary and redundant data in File Explorer to save more space.

How do I resize my SSD after cloning?

To resize SSD after cloning, you can make use of Disk Management. Here are the steps:

• Press Win + X > Disk Management.
• Right-click the partition and select Extend Volume (if unallocated space exists).
• If partitions are locked, use third-party tools like EaseUS Partition Master to adjust sizes.
• Ensure 4K alignment for optimal performance.

Can you clone a 1TB HDD to 500GB SSD?

It depends on how much data is saved on the HDD. If the used space on the 1TB HDD is under 500GB, you can clone HDD to SSD successfully. Otherwise, the process won't be completed, and some of the data will get lost. EaseUS Disk Copy allows your to adjust the disk layout while cloning, allowing you to adjust partition to fit the smaller SSD.