By Emily / Last Updated July 6, 2020

As we all know, when setting up a new disk on Windows computer, we will receive a message saying “You must initialize a disk before Logical Disk manager can access it”. That is to say, we need to initialize the new hard drive to either MBR or GPT before using it for data storage. Today, we will explain the difference between GPT and MBR and introduce great free MBR to GPT converters.

Initialize Disk

Basics you should know about MBR and GPT

MBR (Master Boot Record) and GPT (GUID Partition Table) are two different partition styles for hard disks. MBR is an old hard disk style to manage the partitions while GPT is the latest standard for disk partition management. They mainly differ in the disk size, partition number limitations, etc.

①Disk Size: MBR disk only supports up to 2TB in size while GPT disk could support up to 18EB in the capacity. When your MBR disk is over 2TB, the rest space will be shown as unallocated space in Disk Management and cannot be used.


②Primay Partition Number: On the MBR disk, you are allowed to create up to 4 primary partitions. To create more partitions, you need to make the 4th partition as an extended partition firstly, and then you can create more logical partitions. On a GPT disk, you can create 128 primary partitions at most.

③Data Storage Method: On the MBR disk, the partitioning and boot data is stored in one place, so if the data is overwritten or corrupted, the enter disk will be unusable. By contrast, GPT disk saves multiple copies of data across the disk, so it is more robust and can be recovered when something goes wrong.

Why need a free MBR to GPT converter?

Since GPT comes with the mentioned-above advantages over MBR, you might need an MBR to GPT converter to change partition style from MBR to GPT in Windows 10/8/7 in the following cases:

  • Make the fullest use of a large hard drive which is over 2TB and don’t want to waste the rest space surpassing 2 TB.

  • Need more than 4 primary partitions to store different types of files.

  • Deal with the error message “Windows cannot be installed to this disk. The selected disk has an MBR partition table. On EFI systems, Windows can only be installed to GPT disks” during OS installation.

Three free MBR to GPT converters for Windows 10/8/7

Generally speaking, there are 3 different free converters for Windows users to convert MBR to GPT: Disk Management, Diskpart and a third-party partition manager tool. Next we will show you how to use those three tools to convert MBR to GPT in Windows 10/8/7 step by step.

1. Free convert MBR to GPT via Disk Management (Data Loss)

Disk Management is a Windows native tool for users to perform some basic disk partition management tasks such as formatting/creating/deleting/extending/shrinking partition. To free convert MBR disk to GPT disk via this tool, you need to first delete all partitions on the target MBR disk to make it an unallocated disk space, then you can complete this conversion.

So, if you want to convert disk to GPT without data loss, you had better back up MBR disk before doing as below:

1. Right click “My Computer/This PC” -->”Manage”-->”Disk Management”.

2. Right-click on each partition on the disk you want to convert and select "Delete Volume" to clean the disk.

Delete Volume Windows 10

Step 3. Right-click on the target disk, and select "Convert to GPT Disk".

Convert To Gpt Windows 10

Then follow the hints to finish converting MBR to GPT. It won’t take a long time to finish this operation. After this, you can restore the data you backed up beforehand to this GPT disk.

2. Free change MBR disk to GPT via Diskpart (Data Loss)

Similar to Disk Management, Diskpart is also a Windows built-in tool for users to manage their disk partition. It also only supports converting an empty disk to GPT, so you need to delete all volumes on disk before using this free MBR to GPT converter.

1. Press Win+R together on your keyboard, type cmd in the Run dialogue and press Enter to open Command Prompt window.

2. In the Command Prompt windows, type diskpart and hit on Enter to launch the Diskpart tool. Then run the following commands in turn and press Enter after each one.

  • list disk

  • select disk <disk number>

  • clean

  • convert gpt

Convert Gpt Cmd Windows 10

After that, you can type "exit" and press Enter to close this window. Then you can see it is converted to be GPT style in Disk Management.

3. Free convert disk to GPT via partition software (Data Safe)

The first two free MBR to GPT converting tools require you to delete every existing partition on the MBR disk, which will cause data loss. If you want to convert MBR to GPT without deleting volume and losing data, the free parition manager-AOMEI Partition Assistant Standard can satisfy your requirements best.

It is not only a free MBR to GPT converter, but also a free GPT to MBR converter. Therefore, no matter you want to convert MBR to GPT, or GPT to MBR in Windows 10/8/7, it can ensure a successful conversion with keeping all partitions safe in the target disk.

1. Free download the MBR to GPT converter. Install and run it. Right-click the target MBR disk and select “Convert to GPT Disk” . Here you can see there is a NTFS partition on the disk.

Convert 3tb Disk To Gpt

2. In the mini window, click “OK” to confirm the operation.

Ok 3tb

3. Click “Apply” button to commit the conversion.

Apply 3tb

Wait for a while, the conversion between MBR and GPT will be done easily and effectively without causing data loss.

AOMEI Partition Assistant Standard only supports converting data disk between MBR and GPT styles without deleting partitions. For converting boot disk between MBR and GPT, please upgrade to AOMEI Partition Assistant Professional Edition.
To convert GPT to MBR without operating system or vice versa, you can create a bootable media, boot your PC from it to enter Windows PE mode to finish the conversion
If you want to convert GPT to MBR or MBR to GPT in Server 2003/2008/2012/2016/2019, you can try AOMEI Partition Assistant Server.


Compared with Windows native Disk Management and Diskpart, AOMEI Partition Assistant Standard is a better free MBR to GPT converter. Besides, it can handle many other difficult disk management operations, such as cloning MBR disk to GPT, migrating OS drive to SSD or HDD, merging partitions and more.