By AOMEI / Last Updated December 17, 2020

Why migrate MBR OS to GPT disk?

"My Windows 10 operating system is pre-installed on the hard disk drive with 2TB space, and it is initialized to be MBR format. But now it runs out of space and so I am planning upgrade this 2TB HDD to a new 4TB HDD. But the 6TB needs to be GPT format. So is there a way to migrats OS from MBR disk to GPT disk?"

MBR and GPT are two different partition styles. And in some aspects, the GPT is better than the MBR format. For example, it can support 2TB+ hard drive and contain up to 128 primary partitions. Besides, the GPT disk uses the UEFI boot mode, which is relatively advanced than the Legacy BIOS.UEFI can directly boot OS after initialization and skip the BIOS self-test process, finally leading to a faster boot. So many users want to move OS from MBR to GPT disk to enjoy more effective disk space and optimize PC performance.

Boot Process

Choose a reliable MBR OS to GPT migration tool

To finish the OS migration from MBR disk to GPT disk, the easiest way is to choose a reliable Windows migration tool. Here we would like to recommend the AOMEI Partition Assistant Professional. Its “Migrate OS to SSD Wizard” can migrate system-related partitions from one disk to another and make the destination disk bootable.

Unlike most of other data migration software, it won’t convert the destination disk to MBR while migrating OS from MBR to GPT. It can directly transfer MBR OS to GPT disk and create an EFI partition and MSR partition so that you can boot from cloned GPT disk smoothly after the migration. What’s more, you can adjust the partition size on the destination disk during the migration. Its demo version is available for your free download.

Try Free Demo Win 10/8.1/8/7/XP
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Easy steps to migrate OS from MBR to GPT

Now, you can do as the following steps to learn how to transfer Windows 10/8/7 operating system from MBR disk to GPT. Of course, you have to verify the computer’s motherboard supports UEFI boot mode and make sure it is enabled in BIOS before you boot from the GPT disk.

Step 1. Install your GPT disk in your computer or connect it with a SATA-to-USB adaptor and ensure it is recognized.

Sata To Usb Cable

Step 2. Run AOMEI Partition Assistant Professional and you can see all the partitions and disks available. Make sure the GPT disk has some unallocated space. If it does not, you can shrink or delete partitions on it to generate some such space. Then select the option “Migrate OS to SSD”.

Migrate Os Wizard

Step 3. In the next pop up window, select the unallocated space on the GPT disk as destination location.

Select Disk Space

Step 4. In the next screen, you can adjust the partition size on the disk if needed and then click “Next”. You can also resize system partition after the migration without data loss.

Resize Partition

Step 5. Here comes a note on how to boot from the destination disk. Read it and click on “Finish”.

Boot Note

Step 6. Preview the partition layout and click "Apply" to apply all operations if no problem.


The process will be complete under “AOMEI Pre-OS mode”, which will restart your computer, so save everything you are editing before the migration. After you migrate MBR OS to GPT disk, make sure you have enabled UEFI boot mode in BIOS before trying to boot computer from the GPT disk.


Obviously, with AOMEI Partition Assistant Professional, you can easily migrate MBR OS to GPT disk and boot from it without any issues. Additionally, it also allows you to do MBR to GPT conversion without data loss, and vice versa, so you can also convert your MBR disk to GPT, or convert GPT to MBR before system migration. If you want to transfer Windows Server OS between MBR and GPT disks, you can use AOMEI Partition Assistant Server.