By Emily / Last Updated October 24, 2019


GPT (GUID Partition Table) and MBR (Master Boot Record) are two different disk styles. By contrast, MBR is older than GPT. Besides, they are quite different in the following aspects.

  • MBR disks adopt the standard BIOS partition table. GPT disks adopt unified extensible firmware interface (UEFI).

  • All Windows can boot from MBR disks. Only 64-bit versions on UEFI-based Windows 10/8/7/XP/Vista and Windows Server 2003/2008/2012/2016 can boot from GPT disks. On 32-bit version, GPT disks can only be used as data disk.

  • MBR disk supports up to 4 primary partitions, or 3 primary partitions and 1 extended partition. GPT disk supports up to 128 primary partitions.

  • MBR supports up to 2TB disk, GPT disk supports up to 256TB for a partition.

  • On MBR disks, the partitioning and boot data is saved in one place. If this data is overwritten or corrupted, it is difficult to recover. But GPT makes several copies of this data across the disk, so it’s more robust and you can easily recover corrupted data when necessary.

Need to convert SSD from MBR to GPT

From the first part, we know the MBR and GPT has their own unique features. Sometimes, you will have to convert an SSD drive to GPT for some reasons.

The most important one might be that your SSD drive is larger than 2TB (surpassing its disk size limitation) and the beyond size cannot be used and displayed, leading to your SSD showing wrong size. Or when you need to create more than 4 primary partitions on your SSD drive, then converting it from MBR to GPT is necessary.

Convert SSD to GPT using Command Prompt (Data Loss)

When it comes to converting SSD drive to GPT, you can make use of Disk Management. But only when you delete all partitions on the SSD drive, then you can convert it to GPT successfully, or you will meet “Convert to GPT Disk greyed out” issue. Besides that, you can also convert SSD to GPT via Diskpart (Command Line), which also requires you to remove all partitions on the selected SSD drive.

Importance: To avoid data loss caused by deleting partitions, it is always wise to backup anything important via a free backup software first.

Step 1. Click “Start” button, type “cmd” in the “Search” box, right click the pop-out Command Prompt icon and select “Run as administrator”.

Step 2. Then, input “diskpart” and press “Enter” to run the utility.

Step 3. Type in “list disk” and press “Enter”: get a list of all disks on your computer.

Step 4 Type in “select disk n” and press “Enter”: n represents the number of the SSD drive you want to convert to GPT.

Step 5. Type in “clean” and press “Enter”: delete all partitions on the SSD drive to make it an empty disk.

Step 6. Finally, type in “convert gpt”. and press “Enter”.

Convert SSD To GPT CMD

A GUI tool to convert SSD to GPT without data loss

No matter you use Disk Management or Diskpart, it is a must step to clear selected SSD drive before you can successfully convert it to GPT or MBR. So you might wonder is it possible to convert SSD to GPT without deleting partitions/losing data?

Yes, it is possible when you use a third-party software called AOMEI Partition Assistant Professional. This software allows you to convert data and system disks with partitions into GPT or MBR styles without data loss in Windows 10/8/7.

That is to say, there is no need to delete all partitions first! Next we will show you how to convert SSD to GPT via AOMEI Partition Assistant Professional. You can download the free Demo Version to have a try.

Step 1. Install and run the software. Right click the SSD drive you need to convert from MBR to GPT, and select “Convert to GPT Disk”.

Convert 3tb Mbr Disk To Gpt

Step 2. Click “OK” to confirm your operation.

Ok 3tb Disk

Step 3. In the main interface, click “Apply” to start converting disk to GPT style.

Apply 3tb


No matter you want to convert SSD to GPT via Command Prompt or a GUI tool, you know how to do it now. To evade the hassle of backing up data and restoring them later, AOMEI Partition Assistant is my preference.

Besides, the Pro version can help you clone GPT disk to MBR, or MBR to GPT, migrate OS to SSD drive, optimize SSD drive performance and securely erase SSD. If you want to convert hard disk to MBR or GPT in Server computer, please try AOMEI Partition Assistant Server.