MBR and GPT are two different partition styles for disk configuration. MBR stands for Master Boot Record, using the standard BIOS boot mode. GPT is the abbreviation of GUID Partition Table, using the Unified Extensible Firmware Interface (UEFI) boot mode. The obvious benefits of using GPT disks include that you will be able to :
◗Make the fullest use of large hard disk which is over 2TB because MBR disk can only support 2TB at most.
◗Have more than 4 primary partitions on each disk because MBR disk can only contain 4 primary partitions-if you want more, you have to make one of your primary partitions an “extended partition” and create unlimited logical drives inside it.
◗Enjoy UEFI boot mode that offers secure boot and prevents boot-time viruses from loading.
So, when building Windows Server 2022/2019/2016/2012 or Windows 10/8/7, a large number of users would like to choose GPT disk style instead of MBR. If the default partition style is MBR, you can convert the basic disk from MBR to GPT in Server 2019 or other operating systems.
3 Methods to convert MBR to GPT in Server 2022/2019/2016/2012
Now, we will discuss how to convert MBR to GPT in Windows Server 2019. Three different methods are recommended. Check them out one by one and choose a proper one based on your requirements and situation.
Before you convert a disk, backup partition or data on it and close any programs that are accessing the disk.
1. Convert MBR to GPT via Server 2019 Disk Management (Data Loss)
First of all, you can use GUI Server inbuilt Disk Management, which can convert an empty disk from MBR to GPT or GPT to MBR. So, you have to delete all existing partitions on the MBR disk before conversion.
Step 1. Press “Windows+R” to open “Run”, type “diskmgmt.msc” in the box and press Enter.
Step 2. If the disk contains any partitions or volumes, right-click each and then click “Delete Volume”.
Step 3. Right-click the MBR disk that you want to change into a GPT disk, and then click “Convert to GPT Disk”.
Step 4. Follow the instruction to finish the conversion.
This method is only proper for converting data disk between MBR and GPT in Windows Server 2019/2016/2012/2008. You cannot use it to convert system disk because you are not allowed to delete the system partition within Windows Server.
2. Change MBR disk to GPT using Command Line (Data Loss)
Compared with Disk Management, Command Line can convert data disk and system disk as long as it does not contain any partitions. To convert non-system disk, you can perform it within Windows Server.
Step 1. Press “Windows+R” to open “Run”, type “cmd” in the box and press Enter.
Step 2. In the pop-out Command Prompt Window, type “diskpart” and press “Enter”.
Step 3. When diskpart.exe is launched, input the following commands in turn:
select disk # (# is the target disk number)
Running the clean command will delete all partitions or volumes on the disk. If the MBR disk has no partitions, this command can be neglected.
To convert Server 2019 system disk to GPT, you need to do as below with using the Server 2019 setup CD:
Step 1. Boot computer from the Server 20019 setup/installation CD. Or you can burn the Server 2019 to USB to create a bootable USB stick.
Step 2. On the first screen, select installation language, Time and keyboard layout the click “Next“.
Step 3. In the next window, click “Repair your computer”.
Step 4. Press "Shift + F10" keys together on the keyboard. This will open the command prompt window:
Step 5. Then execute the commands as above (list disk->select disk->clean->convert gpt).
After converting system disk within WinPE environment, you need to reinstall Windows Server 2019 from scratch.
3. Convert MBR to GPT with Server partition manager (without data loss)
Briefly, the first method can convert an empty non-system disk to GPT and the second method is able to convert blank system and non-system hard disks to GPT. But it requires you to reinstall OS and other programs from scratch afterward. So, is there any way to convert boot disk and data disk without deleting existing partitions?
There is such a way to convert MBR to GPT in Windows Server 2019 without data loss. That is to resort to a third party Server Partition Manager like AOMEI Partition Assistant Server. This software can convert both boot disk and data disk between MBR and GPT partition styles without deleting volumes. So, all the contents on the disk will be safe. Now you can download its demo version for a free trial and refer to the following tutorial learn how to convert system disk when the Server is running.
To avoid data loss caused by improper operation or sudden power failure, it is always advised to back up system in advance.
Step 1. Install and run AOMEI Partition Assistant Server. Right-click the disk you want to convert and choose “Convert to GPT Disk”.
Step 2. In the pop-out window, click “OK” to confirm this operation.
Step 3. Back to the main interface, click “Apply” to commit the pending operation.
If you need to convert MBR to GPT in Windows Server 2019 without loading operating system, you can first create a bootable media (USB stick).
Step 1. Plug an empty USB drive to a working Server computer. Install and run AOMEI Partition Assistant Server on that computer as well. Right-click the “Make Bootable Media” option.
Step 2. Choose the inserted USB drive and click “Proceed”.
Step 3. Wait for the process to be done.
Then plug the bootable USB drive into the Windows Server 2019 computer that contains the disk you want to convert into GPT. Reboot it and enter BIOS environment to change boot order to boot computer from the destination USB stick. At last, do as above to convert disk from MBR to GPT or GPT to MBR without loading OS.
After reading this post carefully, you will be clear about how to convert MBR to GPT in Windows Server 2019 through three different methods. AOMEI Partition Assistant Server is compatible with all editions of Windows Server 2022/2019/2016/2012/2008/2003and Windows 10/8/7/XP/Vista. So, this method can be used to convert MBR to GPT in all Server and Windows PC.
Apart from converting disk partition styles without losing data, AOMEI Partition Assistant Server also has many other amazing functions such as migrating OS to SSD/HDD, extending NTFS boot drive without reboot, converting primary drive to logical or logical to primary drive without data loss, convert dynamic disk to basic one without deleting volumes, changing hard drive serial number without losing data, etc.
There is an AOMEI Partition Assistant Unlimited Edition for you if you want unlimited usage within one company. And a great function, "Create Portable Version" is available in AOMEI Partition Assistant Unlimited. The function enables users to create AOMEI Partition Assistant to a removable device so that users can directly run it on target computers without installation.