By Bryce / Last Updated December 10, 2020

Can I clone MBR to GPT SSD directly?
MBR VS GPT & Legacy VS UEFI
How to clone MBR to GPT disk without boot failure?
Follow-up work after MBR to GPT disk copy

Can I clone MBR to GPT SSD directly?

“I have a 500GB MBR partitioned disk with Windows 10 installed on. I want to replace it with my newly purchased 1TB GPT partitioned SSD while I don’t want to reinstall Windows and all other applications on GPT SSD? Can I just clone my MBR system disk to GPT disk directly and boot from the cloned drive without failure?”

MBR VS GPT & Legacy VS UEFI

Before making a decision of duplicating MBR disk to GPT, it's wise to have a basic understating of the differences between MBR and GPT disks.

Legacy BIOS, an essential firmware can activate all necessary components for boot. It is gradually replacing by UEFI (Unified Extensible Firmware Interface). UEFI supports GPT disk and boot faster as UEFI boots the operating system and saves the BIOS testing process and Legacy BIOS will wake up the hardware firstly, and then load bootloader to initialize Windows.

All in all, if your OS is 64bit and the computer motherboard supports UEFI boot mode, it's wise to clone MBR system disk to GPT and then use UEFI boot mode. To check whether your PC support both Legacy and UEFI, enter System Information window (press Windows +R, input "msinfo32" and click "OK")and view BIOS Mode.

How to clone MBR to GPT disk without boot failure?

Make sure that the OS supports GPT disk and the motherboard supports UEFI boot mode. Then, you can easily clone (system) MBR disk to GPT SSD/HDD via a disk cloning tool, AOMEI Partition Assistant Professional.

It can clone MBR disk to GPT SSD or HDD without requiring you to convert the destination GPT disk to MBR partition style and It allows you to clone GPT disk to MBR as well.
It supports you to transfer only OS-related partitions as well (not including data partition) from MBR disk to GPT disk via Migrate OS to SSD function.
It can make 4K alignment to improve SSD’s performance during the cloning process.
The Professional edition is for Windows 10/8.1/8/7 and you can use AOMEI Partition Assistant Server if you are using Windows 2019, 2016, 2012, or 2008.

You download its demo version to have a try!

Now, connect the GPT SSD to your computer and make sure it can be detected. Install the software and have a look at how it clone MBR to GPT SSD:

Step 1. Run AOMEI Partition Assistant Professional and choose All Tools > Disk Clone Wizard in the main interface.

Disk Copy Wizard

Step 2. A window will pop up. Here you can choose a way to copy MBR disk to GPT based on specific situation. Here I choose Clone Disk Quickly. To clone BitLocker encrypted hard drive, you need to choose the second option.

Copy Disk Quickly

Step 3. Choose the MBR system disk as the source disk.

Select Source Disk

Step 4. Select the GPT disk as the target disk. When it is SSD, check “Optimize the performance of SSD…

Select Destination Disk

Step 5. Here you can edit partitions on the target disk.

Edit Disk

You’ll be prompted by a note about how to boot operating system from target disk. Read and remember it. Then, click “Finish”.

Finish

Step 6. You’ll be in main interface. Confirm your operation and click "Apply">"Proceed" to execute it.

Apply

Notes:

  • When you clone MBR disk to larger GPT disk, there might be unallocated space after cloning, you add the unallocated space to another drive or create a new partition with the unallocated space to make full use of it.

  • After making sure that you can boot the computer from the GPT destination disk, if you want to give up your old MBR source disk, you can use AOMEI Partition Assistant Professional to wipe the old hard drive completely and irrevocably.

Follow-up work after MBR to GPT disk copy

After cloning the MBR disk with OS installed to GPT, since the boot mode for MBR and GPT is different, you need to change boot mode from Legacy to UEFI:

1. Reboot your computer and press a functional key (usually, F1, F2, F3, or F10) repeatedly to enter the BIOS setup when you see the first screen.

2. Under the BOOT tab, choose UEFI/BIOS Boot Mode and change the Legacy to UEFI. Then, save and exit the interface.

PS.: If you want to keep both the old disk and new disk, to boot from the target drive, you also need to set the new drive as the prior boot device in BIOS.