How do I convert MBR to GPT without losing data?

[RebeccaLeee]

I'm currently facing an issue where I need to convert a disk from MBR (Master Boot Record) to GPT (GUID Partition Table) without losing any data stored on it. The disk in question contains important data that I cannot afford to lose or corrupt during the conversion process. I’m looking for the safest and most effective method to do this. Can anyone recommend reliable tools or provide a step-by-step guide to ensure a smooth conversion?

[#2]

If you are considering whether to choose paid software to convert MBR to GPT or to use free software, if you have enough budget, I personally recommend that it is better to use paid software, which has many features and stability, and more importantly, the service of paid software is comprehensive and avoid data loss as much as possible.

[#3]

Partition Master Pro is a very popular and powerful Windows utility that allows users to manage and control their disks and partitions. One common task that users may need to perform is converting a disk from Master Boot Record (MBR) to GUID Partition Table (GPT) without losing any data.

To convert an MBR disk to a GPT disk without losing data using Partition Master Pro, follow the steps in below:

1. Before making any changes to your disk, it's always a good idea to back up your important files and data to avoid any potential data loss.

2. Download and install Partition Master Pro. Now, open the program and go to Disk Converter -> Convert MBR to GPT.

3. Select the target MBR disk that you tend to convert to GPT, and click "Convert" to start the conversion.

[#4]

@RebeccaLeee 

Try this two commands on your Windows, it's an easy way to convert MBR to GPT.

1. mbr2gpt /validate /allowFullOS
2. mbr2gpt /convert /allowFullOS

[#5]

Here is the official guide to convert mbr to gpt using the built-in MBR2GPT.exe:

Change a Master Boot Record (MBR) into a GUID partition table (GPT) disk | Microsoft Learn

MBR2GPT.exe is a command-line tool provided by Microsoft for converting a disk from the Master Boot Record (MBR) to the GUID Partition Table (GPT) partition style on Windows 11. This tool is useful for modernizing disks to take advantage of features like Secure Boot and larger disk sizes. It can be run as part of the Windows Setup process or manually from an elevated Command Prompt.

However, this process will format the drive and delete all data from it. To convert mbr to gpt without losing data, you have to use third-party software to do that.

[#6]

@RebeccaLeee 

Windows 10’s MBR2GPT tool: This is a command-line tool introduced in Windows 10 Version 1703 and is designed to convert a disk from MBR to GPT easily, but will erase everything from your disk before converting. if you don't have important data in your disk then you can wipe it then convert it to GPT.

[#7]

Here is an useful tutorial for converting mbr to gpt using the free gdisk software:

https://gist.github.com/cjyar/cd5ea76a8692516767672ffc2883df92

The goal is to keep all data, just rewriting the partition table. But do make backups before you begin!

[#8]

You can make a bootable Linux rescue USB and follow the steps in this tutorial to convert MBR to GPT without losing any data:

https://askubuntu.com/questions/1314111/convert-mbr-partition-to-gpt-without-data-loss

P.S. Please back up your data first. This is very important action to protect your data.

[#9]

Some older operating systems or BIOS/UEFI firmware may not support GPT. Before converting MBR to GPT, ensure that your system and any installed operating systems are compatible with GPT.

[#10]

It seems MBR2GPT doeson't work for me while I'm trying to convert main disk from mbr to gpt, when validating the disk in Windows PE using "mbr2gpt /validate" I get the following output:

MBR2GPT: Attempting to convert disk -1
MBR2GPT: Retrieving layout of disk

Anybody knows this error and how to fix it?

[#11]

@Ganesan1450 

It should be easy to fix, first, check your disk configuration by diskpart command, like “list disk”, it will list your boot and you can see GPT or MBR column. 

If it isn't GPT,  then try the command "mbr2gpt /disk:{number you found} /validate", so for example "mbr2gpt /disk:0 /validate". 

but if you're not familar with command, and there is a risk of doing in this way, you can use some professional MBR to GPT convreter with UI.

[#12]

I bought an external SSD and want to install Windows 11. However, it says Windows 11 can't be installed on this partition because it is not GPT. How can I convert MBR to GPT in this case for my external drive?

[#13]

I do not understand why would somebody recommend paid software for this in 2024. You should not really rely on any software to keep your data valid in this type of operation anyways. And everyone should have a backup. So just update the backup and use gparted live and put the data back. What is so hard on this?

[#14]

GENIUS !!!! This worked for me and you saved me HOURS of work. Thank you

[#15]

@Everlynokc 

It worked, thanks a lot

[#16]

It worked, thanks a lot.

[#17]

@RebeccaLeee 

The disk management function of Windows can convert MBR to GPT, but you must delete all partitions before converting. So this is not a good choice

I follow the guide from THIS URL smoothly converting convert MBR to GPT. 

https://www.pcworld.com/article/2047620/convert-mbr-to-gpt-without-losing-data-in-windows.html

[#18]

@Everlynokc How much should I shrink it?

[#19]

To convert an MBR disk to GPT without losing data, you can use the built-in Disk Management tool or third-party software. Here's a method using Disk Management:
Backup your data to ensure you don't lose anything in case something goes wrong.
Open Disk Management by pressing Win + X and selecting it from the menu.
Delete all partitions on the MBR disk to create unallocated space. You must back up the data from these partitions first.
Right-click on the disk label (not the partitions) and select Convert to GPT Disk.
Recreate partitions and format them as needed.
For a more reliable approach, especially with large amounts of data or if you prefer not to delete partitions, consider using third-party software with GPT partition recovery capabilities. These tools often offer non-destructive conversion options that preserve your data during the transition.