Windows users frequently run into problems when trying to utilize MBR2GPT to convert the disc to a GPT partition, sometimes during the reinstallation of the most recent version of Windows. However, you must understand MBR2GPT before attempting the solution. The post provides several ways to convert disk mbr to gpt and it also includes fixes for the MBR2GPT is not recognized server 2016 issue.
Background Introduction
Users may want to convert disk from MBR to GPT due to different causes: Windows OS upgrade, new disk added, change disk property, etc.
What is the MBR2GPT tool or mbr2gpt.exe?
Without erasing any data from the disk, the MBR2GPT.exe tool acts as a converter to change the Master Boot Record, or MBR, to a GUID or GPT partition table from Windows 2019/10(Windows 10 versions 1703 or higher).
Conditions: MBR2GPT.exe would only work under the following conditions.
1. The MBR disk system partition is set as active on the disk;
2. The disk does not contain any extended or logical partitions;
3. This MBR disk contains 3 primary partitions at most;
4. All partitions are using Windows file systems instead of Ext2, Ext3 or Ext4(Linux file system);
5. Your computer motherboard supports UEFI boot mode;
Or you may receive errors:
Step 1. Create bootable Windows Server 2016 disc or USB drive with the corresponding ISO files.
Step 2. Boot from the bootable media, click Next in the Windows Setup window, and then click Repair your computer.
Step 3. Click Troubleshoot in next window, then click Command Prompt.
Step 4. Then input the following two commands in turn and press Enter after each one.
● cd..
● mbr2gpt /convert
If your disk does not meet the conversion standard, some possible errors:
Server 2016 mbr2gpt convert validating error or conversion failed? Try the following changes.
Change your disk to get it ready for the mbr2gpt conversion.
Note: If the above changes are not easy to operate on your machine, you may try third party software such as Partition Resizer Server which can do the above conversion without your disk changes.
Partition Resizer Server can help backup disks, copy partitions as well as convert disk to GPT without losing data. Here are the steps.
Step1: Download and install Partition Resizer Server on your Server 2016, and open the program
Step2: Right click the disk in Partition Resizer Server, and go to option: Convert to GPT Disk
Step3: Confirm the changes and start the conversion by clicking the Apply Changes in the software.
For the system disk, you need to run the OS from bootable iso and run Partition Resizer in WINPE to convert system disk from MBR to GPT without data loss.
Step1. You need to insert a blank CD, DVD or USB to computer in advance. Without CD/DVD/USB, you need to rely on third-party burn software to make bootable disk.
Download Resizer Server portable version or the partition magic bootable iso
Step2. Run the software and select "Bootable media" (You need to install Windows AIK/ADK).
Step3. Select the option to create bootable disk and then follow the wizard to complete it.
And then an iso file will be available in the end.
Step 4 - After the software launches in bootable WINPE, right click the disk you want to extend, and then go to option 'Convert to GPT Disk' to get the disk converted GPT without losing files and keep the OS safely.
Caution: please backup data on the disk at first.
Step1: Delete volumes that are in inconformity to such standards(logical, extended, ext2. ext3, ext4, mac file system or more than 3 primary partitions on the disk).
Step2: Convert disk to GPT by right clicking the disk at the front of the disk icon in Disk Management
Note: Disk Management can only convert data disk instead of OS disk to GPT with certain kind of conditions listed in the front of this article (the same ones as mbr2gpt convert cmd). If you do not want to change disk, or convert data/os disk to GPT, you may use Partition Resizer Server which can safely convert disk to GPT without losing data.
You need to update the Windows 2016 by clicking on “Settings”> “System” and update with the latest version. The update will take time, and you must monitor whether the update is confirmed or not.
If the Windows update doesn't proceed, you can move forward with Windows Preinstallation environment creation.
Windows PE helps MBR to GPT conversion; in this case, the conversion can be performed without Windows Server 2019 or Windows 10 1703.
Before going for the procedure, you must download the lastest version of Windows Server and a USB drive to be inserted. Then, ensure you back up the USB drive if it contains essential data, as it will be formatted during the process.
Once done with the backup, follow the below steps:
Step 1: Open the ADK tool, click on the “Download” button after ticking "Install the Windows Assessment and Deployment Kit-Windows 10”(for instance) on the PC, and click on “Next”
Step 2: Follow the Next prompts several times.
Step 3: Click on the “Deployment Tools” and “Windows PE Environment,” and click “Install”
Step 4: After finishing the installation, close the Window, and click on the “Start” button> “Windows Kits.” Now right-click on “Deployment” and “Imaging Tools Environment,” select “More,” and tap “Run” as “Administrator.”
Step 5: A command line window will pop up, click on it: “copype amd64 USB drive letter:\WinPE64” and burn Windows PE to a USB drive
Step 6: The process will take time to complete. Next, boot the USB drive after typing the command: “makewinpemedia/iso USB letter:\winpex64 USB letter:\ winPEx64\WPE64.iso.”
The process does not end here. After the progress reaches 100% and “Success” pop up on your Windows screen, close your PC and boot it from the WinPE drive.
Follow the below steps to complete it:
Step 1: Click on the BIOS key when it appears during the booting process.
Step 2: Type BIOS setup, select boot tab, and again type Change boot order
Step 3: Choose the USB drive and boot your PC
Step 4: While booting up, type Windows PE, and click on MBR2GPT. EXE to change the disk to GPT.
Change#1 Delete partitions that Windows does not recognize in Disk Management
Change#2 Convert partition to primary from logical
Also read: how to change partition from logical to primary (3 ways)
Change#3 Delete partitions if there are over 3 primary partitions on the disk (It can be done under Disk Management or with diskpart cmd or software)
Change#4 Set the system partition as active partition on the disk (This can be done in disk management, or with software)
Also read: how to set partition active
How can you use MBR2GPT?
The usage is as follows:
Tips: While you perform the conversion from MBR to GPT to boot in UEFI mode, ensure the device supports UEFI.
Windows Server 2019 old versions does not support mbr2gpt.exe in the system; Windows 7,8 and 8.1 are not included in the supporting list of MBR2GPT.
Between MBR and GPT, MBR is comparatively old and paired with an older BIOS system. On the other hand, GPT is located in the latest UEFI system. Though MBR contains better software and hardware suitability, GPT is the best to catch up.
When the disk contains more than 3 primary partitions, when it's non OS disk, when there are non Windows supported drives on the disk, the convert to gpt option would grey out in Windows Server 2016 disk management.