How to Convert MBR to UEFI without Data Loss on Windows

Can I convert MBR to UEFI?

Many users wonder whether if they can convert disk to UEFI. Strictly speaking, it is not possible to change MBR to UEFI, because MBR is a partition table, and UEFI is a boot mode, they are two totally different conception. However, you can convert MBR to GPT, which is what most people known as UEFI.

MBR (Master Boot Record) that is used to describe how and where the disk information store. If the MBR is corrupted, the OS can't be retrieved by your computer. And the other partition table is GUID partition table (GPT), which is newer than MBR and better for many circumstances.

Note: You can get more information from "What's the Difference Between MBR disk and GPT Disk?".

 While the UEFI (Unified Extensible Firmware Interface) is a specification that defines a software interface between an OS and platform firmware. In a nutshell, UEFI is a new boot mode to start up a computer. 

And usually, MBR disk + BIOS boot mode, and GPT disk + UEFI boot mode are the most common combinations. Next, we will give you more details of MBR and GPT, BIOS, and UEFI and demonstrate how to convert MBR to GPT and change BIOS to UEFI.

About Legacy BIOS and UEFI

Legacy BIOS is a very important firmware that is used to initialize hardware on your PC during the boot process. And a computer won't be started successfully until the BIOS activate all the necessary components for booting up.

After decades of service, Legacy BIOS is gradually replacing by the new firmware-UEFI (Unified Extensible Firmware Interface), which is easier to use. UEFI is much better than Legacy BIOS in many attributes.

● Better compatibility: UEFI works well with the newer partition table, GPT while BIOS cannot support Windows booting from a GPT disk.
● Larger capacity support: UEFI mode allows you to use a disk with a large capacity, while BIOS cannot support a disk more than 2TB.
● Faster speed: The UEFI boot process is faster than BIOS. UEFI directly boots the operating system and saves the BIOS testing process. And the BIOS will wake up the hardware firstly, and then load bootloader to initialize Windows.

Why need to convert MBR to UEFI?

You have known the difference between BIOS and UEFI, there are brief introductions about MBR and GPT. They are different partition table formats, and GPT is the successor of the MBR, so it comes with lots of benefits over MBR:

✦ GPT supports a disk larger than 2 TB in size while MBR cannot.
✦ A GPT disk supports volumes up to 18 exabytes and 128 partitions per disk while the MBR disk supports 2 terabytes in size and 4 primary partitions at most.
✦ GPT partitioned disks have redundant primary and backup partition tables for improved partition data structure integrity.
✦ According to the official news from Microsoft, Windows 11 only supports UEFI boot mode. Thus, if you want to upgrade your Windows 10 PC to Windows 11, you'd better convert your MBR system disk to a GPT disk.

Although UEFI can support MBR disk, MBR plus BIOS, GPT work with UEFI are better for you if you want better use of disk, and break the limit of 2TB. Next, we will show you how to convert MBR to GPT and convert legacy BIOS to UEFI.

How to convert disk to GPT for UEFI boot mode

Before converting MBR(Legacy) to GPT(UEFI) you need to check if your PC supports legacy BIOS and UEFI:

1. Ensure your computer is running with Windows 64-bit 7, Windows 8/8.1, Windows 10, or Windows 11 operating systems.

2. Make sure your computer supports both BIOS and UEFI. If you don’t know, you can press “Win + R” to open Run, and type “msinfo32” to open System Information. And look up “BIOS Mode” to check see if your computer supports the boot mode you want to use.

To convert legacy BIOS to UEFI in Windows 11, 10, 8, 7, firstly, you need to convert MBR to GPT. Follow the context, there are 2 methods for you to convert MBR to GPT for you.

▶ Convert MBR to GPT with an installation CD (Data loss)

If you have an installation CD, you can convert MBR to GPT with Diskpart.

1. Insert the installation CD into your computer, and boot the computer from the CD

2. Then press “shift＋10” to open Command Prompt.

In the Diskpart Window, input the following commands and execute them one by one.

● list disk
● select disk 1 (the disk number of your system disk, normally it is disk 1)
● clean
● convert gpt

Diskpart is a good way to convert files system for computer experts. But you may don’t have an installation CD. Moreover, it will erase all data on the disk, and it is complicated for a novice. An unexpected mistake probably would bring about some issues, since the operation can’t be revoked.

▶ Convert MBR to GPT without data loss

Fortunately, there is a great tool - AOMEI Partition Assistant Professional for you. With this software, you convert MBR to GPT without reinstalling Windows system and deleting partitions/data loss. Let’s see the specific steps. You can download the Demo version to see how to convert disk to UEFI.

Step 1. Install and open AOMEI Partition Assistant. Right-click the system disk and select "Convert to GPT".

Step 2. Ensure you have converted Legacy BIOS to UEFI, and click “Yes” to confirm.

Step 3. In the main interface of AOMEI Partition Assistant, click “Apply” to start the conversion.

And wait for the operation to complete. After that, you can go to "This PC” and open the “Properties”, and you will see the partition table has become to GPT.

How to convert legacy BIOS to UEFI after changing MBR to GPT

After converting MBR to GPT, follow the steps to change BIOS to UEFI.

1. Start your computer and press the functional key (generally, it is F1, F2, F3, F10, or F12, ESC) to enter the firmware interface when you see the first screen. The functional key is different from computers to computers. If you can’t find it, you can refer to the instruction booklet or Google it.

2. Under the BOOT tab, choose the UEFI/BIOS Boot Mode, and change the Legacy to UEFI. Then save and exit the firmware interface.

Conclusion

This is all about how to convert MBR to UEFI. I hope you have a great experience with GPT disk and UEFI firmware. In addition, with AOMEI Partition Assistant, you can also convert file system from FAT to NTFS without formatting, fill hard drive with random data, migrate OS from MBR to GPT disk or GPT to MBR.

If you are a Windows Server user, you need to use the AOMEI Partition Assistant Server Edition to convert MBR (Legacy) to GPT (UEFI).

FAQs about converting MBR to UEFI after conclusion

There are some frequently asked questions about converting MBR to UEFI that you can refer to:

Q: Can I convert from MBR to UEFI on any computer?

Not all computers support UEFI, you need to make sure that your computer's motherboard and firmware must support UEFI before converting, either by checking your system specifications or by consulting the manufacturer's documentation. Usually, if the computer is made in recent years, it supports UEFI.

Q: Can I convert from MBR to UEFI if I'm using a virtual machine?

Yes, it is possible to convert from MBR to UEFI in a virtual machine. The process is similar to that of a physical machine, but you'll need to ensure that your virtualization platform supports UEFI.

Q: What are the risks associated with converting from MBR to UEFI?

Although it is safe to convert MBR to UEFI by using AOMEI Partition Assistant Professional, to avoid the risk of data loss. It is always vital to back up important files before you officially start.

Q: Can I revert to MBR if I encounter problems after conversion?

Yes, it is possible to reconvert to MBR. Same with the steps of converting MBR to GPT, you can convert UEFI to MBR again without losing data.