Windows uses both partition styles Master Boot Record (MBR) and GUID Partition Table (GPT). MBR is an older partition format and supports up to 2TB of partition size with a maximum of four primary partitions. At the same time, the GPT partition style is new and can manage 128 primary partitions and 256TB of partition size.
Converting MBR to GPT is easy if no data is available on your external or internal storage drive. Using the built-in diskpart tool, you can quickly convert MBR to GPT and vice-versa. However, it is very tricky to handle the data if Windows is installed on the disk and you want to convert MBR to GPT format.
If you want to use UEFI boot mode instead of BIOS, you will need to convert MBR to GPT. You can easily change the BIOS settings and select UEFI when you want to install a new Windows operating system on your PC. But, if you have already installed Windows on MBR and now you want to convert the disk to GPT without losing data, it is still possible through the built-in MBR2GPT tool.
BIOS is a piece of code that resides on the motherboard that helps connect the hardware and software. UEFI is the new firmware type that replaces the old BIOS style. It includes several features, including support for partitions larger than 2TB and faster startup, sleep, resume, and shutdown. Besides that, it unlocks new security features available on Windows 11 and 10. For example, the “Secure Boot” feature protects a device’s startup process from malicious programs, and now it is mandatory to install Windows 11.
When do you Need to Convert MBR to GPT?
Both MBR (Master Boot Record) and GPT (GUID Partition Table) partition styles are widely used in Windows devices. However, more and more users are switching their disks from MBR to GPT to get more features. Here is a list of unique moments or situations that you need to convert MBR to GPT:-
- To create more than four primary partitions on a disk.
- To make full use of a disk with more than 2TB space.
- To install Windows on an EFI/UEFI disk.
- When you receive the error message “Windows cannot be installed to this disk. The selected disk has an MBR partition table. On EFI system, Windows can only be installed to GPT disks.”
What are the requirements to use the mbr2gpt tool?
You can use the MBR2GPT tool on a traditional hard drive (HDD), solid-state drive (SSD), or an M.2 drive. But, you should note the following:-
- Turn off BitLocker if you use it.
- Your disk should have sufficient free space.
- The disk should not have more than three partitions.
In this gearupwindows article, you will learn how to convert MBR to GPT in Windows 10 without losing the data.
How to Convert MBR to GPT in Windows 10 without Data Loss?
Before proceeding with the steps, you should check whether your disk uses MBR or GPT partition style. If you note that your PC is using MBR partition style, you can proceed with further steps to convert them to GPT. Also, ensure to take the full backup of your important data. If something goes wrong, you can’t reverse the changes.
To convert MBR to GPT on live Windows 10, use these steps:-
Step 1. Open Command Prompt as administrator. Alternatively, you can also use Windows PowerShell.
Step 2. Type the following command and press the
mbr2gpt /validate /allowFullOS
Step 3. Next, type the following command and press the
mbr2gpt /convert /allowFullOS
Once you complete the above steps, the mbr2gpt tool will reduce the size of the primary partition and change it from MBR to GPT.
How to Change the Firmware Node from BIOS to UEFI?
Once you have converted your primary disk from MBR to GPT, Windows will not boot until you change BIOS to UEFI on the motherboard.
To change the BIOS, you need to press a special key when your PC starts. Although it is different for every PC manufacturer, you can try one of the function keys (F1, F2, F3, F10, or F12), Esc, or Delete as soon as you start your computer. If you still can’t enter in BIOS setup, please check your device manufacturer’s support website for specific details.
On the Boot menu, enable the UEFI option, save the changes, and then your computer should start normally. And, if you plan to upgrade your device to Windows 11, in the UEFI settings, open the boot or security settings page and enable the “Secure Boot” option, and exit the firmware saving the changes.