By Teresa / Last Updated October 23, 2020

UEFI boot vs Legacy BIOS boot

Before you start to copy UEFI boot disk, you may want to know what UEFI boot is and how it is different from traditional BIOS boot.

Unified Extensible Firmware Interface (UEFI) is a kind of PC system specifications that used to define the interface between operating system and system firmware and hardware. This interface is responsible for powering the self-test (POST), connecting operating system, and providing an interface to the operating system and hardware.

UEFI and BIOS are different boot modes and the former is widely used in new computers. UEFI uses different firmware and supports larger hard drive and brings faster boot times and more security features comparing to the traditional one. It also works with the newer partition table, GUID Partition Table (GPT), and is replacing the old one eventually. On the contrary, you may have heard that after converting larger hard drive (over 2TB) from MBR to GPT, to keep the system bootable, one must change Legacy to UEFI in BIOS. That is, UEFI with GPT and Legacy with MBR.

Why clone UEFI GPT disk?

Cloning a UEFI hard disk almost has the same purposes of common hard drives. To sum up, following two reasons come first on the list.

First, upgrade existing UEFI hard disk. Some users want to clone UEFI disk to SSD or larger or newer disk to replace the old one. Obviously, SSD or any new disk would bring much better performance and experience than the disk that has been used for years does. No need to reinstall Windows OS and software for this as well.

Secondly, copy UEFI drive for backup. Sometimes, disk copy has the same effect of disk backup, and it saves times and efforts to restore the image at the same time. Only one thing, disk copy takes up much more disk space on destination than images. It is not a bad idea to do UEFI HDD copy when you have a spare external hard drive around.

Anyway, you probably want to clone UEFI drive with other intentions. However, when you choose the software to clone UEFI disk, make sure it would recognize the GPT partition table. Otherwise, things may be complicated.

Best UEFI clone software for Windows

AOMEI Partition Assistant Professional is the right disk cloning software that will help you clone UEFI HDD to SSD in simple and easy way. Partition on SSD will be aligned during the copy process. Except for cloning the entire UEFI boot disk, you can clone UEFI boot partition only to USB flash drive or external storage. This software recognizes both UEFI GPT disk and Legacy MBR disk, and works quite well in Windows 10, 8, 8.1, and 7.

What’s more, if you need to change UEFI backward to Legacy in the future, you can use this software to convert GPT to MBR without data loss. With its user-friendly interface and simplified steps, even a computer novice can do a great job. Now, let’s get to know steps to clone UEFI disk in Windows 10.

How to copy UEFI disk to SSD without reinstalling in Windows 10?

In the first place, connect the SSD to your machine and make sure it can be detected. If it is new, initialize it to GPT partition style in Disk Management. Install and launch AOMEI Partition Assistant on your Windows 10.

Step1. Right click the GPT boot disk and select “Copy Disk” from the given options.

Copy UEFI boot disk

Step2. Select backup method, “Copy Disk Quickly” or “Sector-by-Sector Copy”. Here will take the first method for example.

Copy Methods

Step3. Select the destination SSD. And remember to check the box in front of “Optimize the performance of SSD” since it is an SSD.

Destination SSD

Step4. Given that you’ve chosen the first copy method, now you can edit partitions with the three copy options. Edit the way you like.

Copy Options

Step5. Now, you will see the virtual result. All partitions on Disk 1 have been copied to Disk 2, with different drive letter. Click “Apply” and later “Proceed” to execute the pending operations.


Step6. (Optional) If you want to boot from the cloned SSD, it is suggested to remove the old UEFI boot disk and leave only the cloned disk to test. If you copy disk for backup only, just disconnect the cloned one and save it to a safe place.


  • Copy Disk Quickly: As stated, it will copy only used space on UEFI boot disk, and you’re allowed to adjust partitions on the destination. Also, this method takes up less time to complete. You can copy large disk to smaller disk as well.

  • Sector-by-Sector Copy: All sectors will be copied so you can recover formatted or deleted data on UEFI disk through this way, only if they haven’t been overwritten. This method requires destination must larger or equal to the source. More time needed as well.


You see, it is quite simple to copy UEFI boot disk to another disk if you choose the right cloning software to assist. If you want to use the old UEFI boot disk as a secondary storage after cloning, you can format it to clean up disk. Try SSD data secure wiping if it is an SSD

AOMEI Partition Assistant also is capable of many other things. For example, you can migrate OS to SSD only and leave data partitions on old HDD. This combination makes full use of HDD’s and SSD’s advantages. To clone UEFI boot disk on Windows Server, you may want to give its Server edition a shot.