В этой статье мы рассмотрим, как изменить режим загрузки Windows на компьютере с BIOS (Legacy) на UEFI + Secure Boot без переустановки операционной системы и без потери данных. Так как в режиме Legacy компьютеры (виртуальные машины) могут загружаться только с дисков с таблицей разделов MBR, при переключении на режим загрузки UEFI нужно будет сконвертировать таблицу разделов диска на GPT (GUID).
В системных требованиях к Windows 11 указано обязательное наличие чипа TPM 2.0 и режим загрузки UEFI+Secure Boot. Есть обходной способ установки Windows 11 без TPM, UEFI и Secure Boot, но он не рекомендуется для использования на продуктивных системах. Поэтому, например при обновлении Windows 10 до 11 на компьютере с MBR загрузчиком желательно включать UEFI (либо воспользоваться неподдерживаемым официально способом обновления до Windows 11 на несовместимом компьютере).
Прежде, чем приступать к конвертации Windows, установленной на Legacy BIOS устройстве в режиме UEFI, проверьте, что ваше окружение соответствует следующим условиям:
- Прошивка материнской платы компьютера поддерживает режим загрузки UEFI. На текущий момент включен режим совместимости с BIOS (проверьте это в настройках BIOS/UEFI устройства и в спецификации к материнке).
- На компьютере установлена x64 версия Windows, с версией как минимум Windows 10 1703 (или Windows Server 2016)
- На компьютере не используется двойной режим загрузки нескольких ОС (Dual-Boot)
- Шифрование Bitlocker для системного диска отключено
- На системном диске используется таблица разделов MBR (количество разделов не более трех)
- На диске достаточно свободного места для создания загрузочного EFI раздела (размер по-умолчанию 100 Мб)
Откройте командную строку PowerShell и проверьте, что компьютер загружается в режиме BIOS (Legacy):
$env:firmware_type
С помощью PowerShell проверьте, что на диске используется таблица разделов MBR и создано не более 3 primary разделов:
Get-Disk
Get-Disk |Get-Partition
Начиная с Windows 10 1703 доступна встроенная утилита Mbr2gpt, позволяющая сконвертировать таблицу разделов диска из MBR в GPT без потери данных. Конвертацию можно выполнить даже в онлайн режиме.
Сначала протестируйте, возможно ли сконвертировать MBR таблицу разделов системного диска в GPT:
mbr2gpt /validate /allowfullos
Если конвертация MBR в GPT возможна, утилита вернет:
MBR2GPT: Validation completed successfully
Если появится ошибка
Disk layout validation failed for disk 0
:
- Проверьте, что на вашем MBR диск создано не более 3 основных (primary) разделов
- Расширенные (Extended), логические (Logical) и динамические разделы должны отсутствовать
- На диске есть как минимум 500 Мб свободного места для создания системных разделов и размещения основной и резервной таблиц разделов GUID
Другая возможная ошибка
Cannot find OS partition(s) for disk 0
указывает на то, что в конфигурации загрузчика BCD отсутствует запись на загрузку в среде восстановлений Wingows. Проверьте это:
reagentc /info
Windows RE status: Disabled
Как включить среду восстановления WinRE описано по ссылке.
После того, как все предварительные проверки пройдены, запустите конвертацию системного диска из MBR в GPT непосредственно из запущенной Windows:
MBR2GPT.EXE /convert /allowfullos
После завершения работы команды, проверьте что таблица разделов была изменена на GPT:
get-disk
Затем нужно перезагрузить компьютер, войти в меню настроек BIOS/UEFI отключить режим Legacy BIOS и переключиться в режиме UEFI+Secure Boot.
На физическом компьютер, чтобы войти в настройки UEFI, нужно при загрузке нажать клавишу
F2
,
Delete
или
F1
. Название и местоположение пункта меню, которые обеспечивает загрузку в режиме Legacy BIOS, отличается в зависимости от прошивки и версии материнской платы. Возможные названия пунктов — CSM (Compatibility Support Module), Legacy Mode, CSM Boot, Legacy OS и т.д. Измените его на UEFI.
Если это виртуальная машина VMware, нужно в настройках ВМ в разделе Boot Options переключиться в режим EFI и включить опцию Secure Boot.
После загрузки проверьте, что используется режим UEFI+ Secure Boot:
Confirm-SecureBootUEFI
Если режим Secure Boot отключен, проверьте что включен режим UEFI командой:
$env:firmware_type
На старых компьютерах с BIOS, которые не поддерживают режим UEFI, можно загружать Windows с внешней USB флешки с MBR. В этом случае на системном разделе можно использовать таблицу разделов GPT. Смотри статью Загрузка Windows с GPT диска на BIOS компьютере (без UEFI).
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How to Change BIOS Mode from Legacy to UEFI Windows 10
By Linda | Follow |
Last Updated
Do you need to convert Legacy to UEFI? If so, you come to the right place. In this post, MiniTool shows you how to do that in detail. You can have a try.
Tips:
In general, on Windows 11, you don’t need to convert Legacy to UEFI. Because once Windows 11 runs, it means that your PC is using UEFI, unless there is something wrong.
Why Do You Need to Convert Legacy to UEFI?
There are many reasons for you to convert Legacy to UEFI. For example:
- The UEFI boot mode uses GPT system disks while the Legacy boot mode uses MBR disks. MBR disks can only use disk space within 2TB while GPT disks break through this limit. GPT disks allow you to create more than 4 primary partitions while MBR disks don’t. MBR disks only allow one active partition while GPT disks allow multiple ones.
- The UEFI boot mode has a faster booting process than the Legacy boot mode.
- The UEFI boot mode supports Secure Boot, which can ensure that no malware tampers with the booting process.
- Windows 11 installation requires the UEFI boot mode. If you need to upgrade from Windows 10 to Windows 11 and you are using the Legacy boot mode, you need to convert Legacy to UEFI first.
Check Whether You Are Using the Legacy Boot Mode
Do you need to convert Legacy to UEFI? You should check whether you are using the Legacy boot mode first. If YES, then you need.
As mentioned above, the Legacy boot mode uses MBR disks while the UEFI boot mode uses GPT disks. Therefore, you can identify the boot mode by checking the type of your system disk because the PC won’t boot up if the disk type and the boot mode do not match. Here is the guide:
- Press the Windows key + R to open the Run box.
- In the Run box, type “diskmgmt.msc” and press Enter to open Disk Management.
- Right-click on Disk 0 and see if there is a “Convert to GPT Disk” option in the context menu. If YES, you are using the Legacy boot mode.
In this part, I will show you how to change BIOS mode from Legacy to UEFI Windows 10.
Stage 1. Convert the System Disk from MBR to GPT
If you are using the Legacy boot mode and want to change it to the UEFI boot mode, you need to convert MBR to GPT before changing the boot mode to UEFI. The reason is that if you don’t convert MBR to GPT, the PC won’t boot after you change the boot mode from Legacy to UEFI.
To convert MBR to GPT, you can use the following 3 ways. Two of them can help you convert MBR to GPT without data loss.
Way 1. Use MiniTool Partition Wizard
MiniTool Partition Wizard is a professional partition manager that not only can help you convert the system disk from MBR to GPT without losing data, but also can migrate OS, clone a hard drive, recover data and partitions, convert partitions between FAT32 and NTFS without data loss, etc.
Here is how to convert MBR to GPT using MiniTool Partition Wizard.
MiniTool Partition Wizard DemoClick to Download100%Clean & Safe
Step 1: Launch MiniTool Partition Wizard. Right-click the system disk and choose the Convert MBR Disk to GPT Disk option from the context menu. Read the warning information and click OK.
Step 2: Click the Apply button to execute the pending operation. After that, the PC won’t boot. You need to go to the next stage to change the boot mode from Legacy to UEFI.
Way 2. Use MBR2GPT
MBR2GPT is a tool offered by Windows and it is usually stored in WindowsSystem32. In addition, this tool is only available on 64-bit Windows 10 version 1703 or later. With this tool, you can also convert MBR to GPT without data loss. Here is how to do that:
- Type “cmd” in the Windows search bar and the Command Prompt app will appear.
- Right-click the app and choose Run as administrator.
- On the Command Prompt window, type “mbr2gpt /convert /disk: 0 /allowfullOS” and press Enter. Disk 0 (usually the system disk) will be converted to a GPT disk.
Way 3. Use Windows Installation Media
If you use this method to convert MBR to GPT, you need to delete all partitions and data on the system disk. Here is the guide:
Step 1: Create a Windows 10 or Windows 11 installation media. Insert the media to your PC and make the PC boot from the media.
Step 2: Go on until you see the Install now window. Then, click Repair your computer button in the bottom left corner. Go to Troubleshoot > Command Prompt. Then, execute the following commands to clean the system disk and convert it to GPT.
- diskpart
- list disk
- select disk 0
- clean
- convert gpt
Step 3: You can then clean install Windows on your PC.
Stage 2. Change the Boot Mode in BIOS
In this part, I will show you how to change the boot mode to UEFI. After that, your PC can boot normally.
- Shut down your PC.
- Power on the PC and press the BIOS key (Del, Esc, F2, etc.) immediately when the PC brand logo appears. You can see the BIOS key at the bottom of the PC logo screen. Or, you can search for it online.
- Now, you are in the firmware. Go to the Boot tab and change the Boot Mode from Legacy to UEFI.
- Save changes and exit the firmware. The PC will boot up automatically.
Tips:
If you don’t see the Boot Mode item, you can see the Boot Option and check whether it starts with UEFI.
How to change BIOS mode from Legacy to UEFI Windows 10? Here is the guide.Click to Tweet
Bottom Line
Do you have opinions on changing Legacy to UEFI? Share them with us in the following comment zone. In addition, if you encounter problems when using MiniTool Partition Wizard, please feel free to contact us via [email protected]. We will get back to you as soon as possible.
About The Author
Position: Columnist
Linda has been working as an editor at MiniTool for 5 years. She is always curious about computer knowledge and learns it crazily. Her articles are simple and easy to understand. Even people who do not understand computer can gain something. By the way, her special focuses are disk management, data recovery and PDF editing.
(Image credit: Mauro Huculak)
If you want to switch the firmware type from the Basic Input/Output System (BIOS) to the Unified Extensible Firmware Interface (UEFI) without modifying the current installation or plan to upgrade from Windows 10 to Windows 11, you can use the «MBR2GPT» tool to convert the drive from a Master Boot Record (MBR) to a GUID Partition Table (GPT) partition style.
Understanding BIOS and UEFI
BIOS is a piece of code that resides on the motherboard that connects the hardware and software. This code has been around for a long time, and while it worked well, it was never designed for modern hardware, and it had many limitations, including limitations to partitions smaller than 2TB.
UEFI is the new firmware type designed to replace the old BIOS style. It introduces additional features, including support for partitions larger than 2TB and faster startup, sleep, resume, and shutdown times. Also, it unlocks new security features available on Windows 11 and Windows 10. For instance, «Secure Boot» is a feature that can protect a device’s startup process from malicious programs, and now it’s a prerequisite to install Windows 11. «Device Guard» gives you more advanced controls for app access, and «Credential Guard» can help prevent pass-the-hash attacks.
In this how-to guide, I’ll walk you through the steps and information to use the Microsoft MBR2GPT command-line tool to convert a drive from MBR to GPT partition style, switch from BIOS to UEFI mode on your device, and enable Secure Boot correctly.
Warning: This is a non-destructive process, but it’s still recommended to make a full backup of your PC before proceeding in case something goes wrong and you need to recover your setup.
Recent updates
These instructions has been updated to ensure accuracy and reflect changes to the process in the operating system.
How to convert a drive from MBR to GPT on Windows 10
Unlike older methods, which require backing up data and reinstalling Windows, the MBR2GPT tool makes it easy to change the partition style quickly. The conversion process adds the GPT components to the MBR partition without modifying the existing partition and leaving the data untouched.
The best approach is to switch to UEFI and perform a clean install of Windows 11. However, if you already have a Windows 10 installation and want to upgrade, you can convert the drive to change the system firmware settings properly. Otherwise, the device will no longer start correctly.
All the latest news, reviews, and guides for Windows and Xbox diehards.
Check MBR or GPT partition style
Before making system changes, check the current settings to see whether the system is set to MBR or GPT using these steps:
- Open Start.
- Search for Disk Management and click the top result to open the experience.
- Right-click the drive (where Windows 10 resides) and select the Properties option.
- Click on the Volumes tab.
- Under the «Partition style» field, if the field reads «GUID Partition Table (GPT),» the drive does not need conversion, but if you see the «Master Boot Record (MBR)» label, you will need to use the conversion tool.
- Click the Cancel button.
Once you complete the steps, you can change the partition style on the computer.
Also, if you need to change the partition, check your device manufacturer’s support website to find out whether the hardware includes support for UEFI before using these instructions.
Convert MBR to GPT partition style (offline)
To convert a drive using MBR to GPT on Windows 10, use these steps:
- Open Settings.
- Click on Update & Security.
- Click on Recovery.
- Click the Restart now button under the «Advanced startup» section.
- Click the Troubleshoot option.
- Click on Advanced options.
- Click the Command Prompt option.
- Select your administrator account and sign in (if applicable).
- Type the following command to validate the drive’s requirements and press Enter: mbr2gpt /validate
- Quick tip: The mbr2gpt.exe is located in the «System32» folder inside the «Windows» folder. If you want to see all the available options, use the mbr2gpt /? command.
- Type the following command to convert the drive from MBR to GPT and press Enter: mbr2gpt /convert
- Quick note: The command output in this image indicates that the conversion has completed successfully, but there was an issue with the Windows Recovery Environment. If this happens, once you’re in the desktop, run the the reagentc /disable and reagentc /enable commands from Command Prompt (admin).
- Click the Close button.
- Click the «Turn off your PC» option.
After you complete the steps, the tool will validate the drive and create an EFI system partition (ESP). The process will also insert the UEFI boot files and GPT components into the partition. The tool will update the Boot Configuration Data (BCD) and add the previous drive letter to the drive.
Convert MBR to GPT partition style (online)
To avoid potential problems, the MBR2GPT tool should always be used offline. However, it can also be run when the system is operational.
To convert a drive from MBR to GPT on Windows 10, use these steps:
- Open Start.
- Search for Command Prompt, right-click the top result, and select the Run as administrator option.
- Type the following command to validate the drive and press Enter: mbr2gpt /validate /allowFullOS
- Type the following command to convert the drive to GPT and press Enter: mbr2gpt /convert /allowFullOS
Once you complete the steps, the command-line tool will reduce the size of the primary partition and change it from MBR to GPT.
MBR2GPT return codes
If the processes are completed successfully, the return code would be «0,» but if the process fails, you may see one of the 11 error codes:
Swipe to scroll horizontally
|
Return code |
Description |
|---|---|
|
1 |
User canceled the conversion. |
|
2 |
Internal error. |
|
3 |
Initialization error. |
|
4 |
Invalid command-line parameters. |
|
5 |
Error on the geometry and layout of the selected disk. |
|
6 |
One or more volumes on the disk are encrypted. |
|
7 |
Geometry and layout of the disk don’t meet requirements. |
|
8 |
Error while creating the EFI system partition. |
|
9 |
Error installing boot files. |
|
10 |
Error while applying GPT layout. |
|
100 |
Successful conversion, but some boot configuration data didn’t restore. |
MBR2GPT important details
The MBR2GPT tool can be used on a traditional hard drive (HDD), solid-state drive (SSD), or NVMe M.2 drive with virtually any version of Windows 10, but you must run it from a Windows 10 (version 1703 or later) installation.
When dealing with a drive using file encryption with BitLocker, you must first suspend the encryption before following the outlined instructions.
While MBR-style drives can have up to four primary partitions, the drive you want to convert can only have three partitions because one additional allocation is required to create the UEFI partition.
Finally, Microsoft designed the tool to convert drives running Windows 8.1, 7, or an older version. However, you can always upgrade the installation to the latest release of Windows 10 and then use the tool to convert from MBR to GPT.
How to change the firmware mode from BIOS to UEFI
After converting the drive to the GPT style, the computer will no longer start until you change the firmware type from BIOS to UEFI in the motherboard.
Typically, this process requires hitting one of the function keys (F1, F2, F3, F10, or F12), the «Esc,» or the «Delete» key as soon as you start the device. However, since these options are always different, it’s best to check your device manufacturer’s support website for more specific details.
On the firmware interface, find the «Boot» menu, enable the UEFI option, save the changes, and then the computer should start normally.
Also, if you plan to upgrade the device to Windows 11 while in the UEFI settings, open the boot or security settings page, enable the «Secure Boot» option, exit the firmware, and save the changes.
Check GPT partition style
To confirm the device is using a GPT partition style, use these steps:
- Open Start.
- Search for Disk Management and click the top result to open the app.
- Right-click the main drive and select the Properties option.
- Click on the Volumes tab.
- Under the «Partition style» field, the information should now read «GUID Partition Table (GPT).»
After you complete the steps, if the partition is running using the correct partition style, you only need to check whether the device uses the UEFI firmware mode.
Check UEFI firmware
To confirm the computer is in UEFI mode and Secure Boot is turned on, use these steps:
- Open Start.
- Search for msinfo32 and click the top result to open the System Information app.
- Click on System Summary on the left pane.
- Check the «BIOS Mode,» which now should read UEFI.
- Check the «Secure Boot State» information, which now should read On.
Once you complete the steps, if the System Information displays the mode as «UEFI,» you have successfully switched the firmware type.
More resources
For more helpful articles, coverage, and answers to common questions about Windows 10 and Windows 11, visit the following resources:
- Windows 11 on Windows Central — All you need to know
- Windows 10 on Windows Central — All you need to know
Mauro Huculak has been a Windows How-To Expert contributor for WindowsCentral.com for nearly a decade and has over 15 years of experience writing comprehensive guides. He also has an IT background and has achieved different professional certifications from Microsoft, Cisco, VMware, and CompTIA. He has been recognized as a Microsoft MVP for many years.
Every time you turn on your computer, you are sometimes greeted by a screen that displays the manufacturer’s information. This is called the BIOS, and it has two main types; Legacy BIOS and UEFI. Older motherboards have legacy BIOS firmware while modern computers come with the UEFI BIOS.
It is possible to completely change the BIOS on your computer, but do so with caution: If you don’t know what you’re doing, it could lead to irreversible damage. We have put together this guide to help you upgrade from Legacy BIOS to UEFI. Let’s get started!
Why Should You Convert Legacy BIOS to UEFI?
Whenever you turn your computer on, you are actually activating the BIOS, which loads the rest of your computer’s hardware. The BIOS of a computer determines how the PC will turn on, from which drive it will boot, and how it will perform basic functions.
Additionally, it is used for identifying and configuring items such as hard drives, floppy drives, optical drives, CPUs, memory, and other equipment in computers.
Old computers come with the Legacy BIOS, which manages the data flow between your operating system and connected devices. However, it has certain limitations. For instance, it cannot recognize drives larger than 2.1TB, and the setup programs are text-only.
On the other hand, modern PCs come with UEFI BIOS, which is extensively customizable and does the same job better. UEFI can support drives 2.2TB or larger thanks to its use of GUID Partition Tables (GPT) instead of the outdated Master Boot Record (MBR). The UEFI stores all the information about initialization and startup in an EFI file called .efi, which resides on an EFI System Partition called ESP. A boot loader program for the operating system installed on the computer is also included in the ESP partition.
To put it simply, switching to UEFI is a worthwhile upgrade that provides you with the following advantages:
- Better performance of the computer as a whole
- Fast booting times
- Removes compatibility issues with Legacy BIOS
Additionally, UEFI is more secure than Legacy BIOS. UEFI’s Secure Boot feature ensures that only approved operating systems can be installed on your computer. However, UEFI can still be vulnerable to certain security attacks.
How to Check if You Are Using Legacy BIOS
You can determine your BIOS version by following these steps if you are not sure which version you are using:
-
Type Create and format hard disk partitions in the search area of the taskbar and click Open. This should launch the built-in Disk Management tool.
-
In the Disk Management tool, right-click on the Windows installation disk (Disk 0) and select Properties from the context menu.
- Go to the Volumes tab inside the Properties window. If you locate Master Boot Record (MBR) next to Partition style, your system is using Legacy BIOS.
-
If you see GUID Partition Table (GPT) instead, then your system is on UEFI already, and you don’t need to do anything else!
Following your determination of which BIOS you are using, you can move on to the practical steps.
The Prerequisites for Upgrading to UEFI
Before you jump into converting Legacy BIOS to UEFI, here are a few things you should know:
-
Your Windows version should be Windows 10 v1703 or higher. In case you do not know which operating system version you are on, press Win + R keys simultaneously on your keyboard. In the text field of the dialog box, type winver and hit Enter. In the About Windows box, you should see your current Windows version.
- Your targeted disk shouldn’t contain more than three partitions. If more than three partitions are present on the Windows 10 installation drive, you can merge or delete them.
- BitLocker does not allow Windows to convert your drive from Legacy BIOS to UEFI. This is why if you are using it, we suggest disabling or suspending BitLocker before you proceed.
- Once the conversion process is complete, you may have to change your firmware settings from Legacy BIOS to UEFI. As the process to switch from one to the other will vary depending on your motherboard manufacturer, ensure you have your manual with you.
- You will not lose your data during the conversion process. However, we recommend that you back up your data to be safe.
How to Convert Legacy BIOS to UEFI
Now that you have verified that your system is running Legacy BIOS and have created a backup of your data, let’s begin the conversion process.
Here is what you need to do:
- Press Win + X keys on simultaneously on your keyboard.
-
Select Shut down or sign out and then click on Restart while holding the Shift key from the context menu that appeared on your screen.
- Your system should not boot into the Advanced Startup screen.
-
From there, click on Troubleshoot.
-
Select Advanced option in the next window.
-
Now, click on Command Prompt.
-
Once you are inside the Command Prompt window, type the command mentioned below and hit Enter to execute it.
mbr2gpt /validate
- This command should validate the targeted disk. Continue with the next step if the Validation completed successfully message is displayed. If any error is displayed, then this implies that the disk or system may not have the capacity to handle the conversion.
-
In case you cannot validate using the command above, execute the following command.
mbr2gpt /validate /allowFullOS
-
Once the disk is validated, execute the following command to complete the conversion.
mbr2gpt /convert
- Windows should now begin the conversion process. Wait patiently for the process to complete and then reboot your PC.
- Upon rebooting, launch the firmware settings screen for your motherboard and switch it from Legacy BIOS to UEFI. Since the steps for this vary depending upon your motherboard, consult your manual for the exact procedure.
- Once done, follow the steps we outlined above to verify whether you’ve been converted from Legacy BIOS to UEFI.
BIOS Updated Successfully
The Legacy BIOS upgrade to UEFI has now been completed successfully. The UEFI system is more powerful and has more advanced features than BIOS. UEFI speeds up boot time and offers security features such as «Secure Boot,» which prevents the computer from being booted by unauthorized or unsigned programs. This makes UEFI the next generation of BIOS.
This is a no-fuss tutorial to help you change BIOS Mode from Legacy to UEFI in Windows 10. We promise it won’t take more than a few minutes. 😄
Basic Input/Output System (BIOS) is the first thing you wake up whenever you power on your computer. It allows for a proper handshake between the operating system and the attached hardware. And from there on, you start using your computer.
BIOS (aka Legacy or Legacy BIOS) was good at what it did from 1975 until 2020; the year chipmakers slowly started to migrate to an efficient alternative: UEFI (Unified Extensible Firmware Interface).
The upgrade ensures:
- Faster boot times and system performance
- Support to hard disks (and partitions) larger than 2.1 TB
- More security and Advanced Graphical User Interface
- Boot Support for both GPT (GUID Partition Table) and MBR (Master Boot Record) (via compatibility mode)
In addition, UEFI’s ability to use the GPT partition table means no practical limitation on the number of partitions.
Why change from Legacy to UEFI in Windows 10?
UEFI has many advantages over Legacy BIOS like:
Performance Boost
Short Booting Times
User-Friendly Interface
Supports bigger Hard disks and Partitions than 2.1 TB
Consecutively, this is more secure and makes your system perform better.
How to Change BIOS mode from Legacy to UEFI in Windows 10
This tutorial is divided into two parts:
- Converting your hard disk from MBR to GPT
- Turning on UEFI from the BIOS setup (that’s up to you)
The second part is specific to the manufacturer. So, check out upfront and get comfortable before going ahead with the first. Chances are, the option for UEFI won’t be in the BIOS if you’re using a really old PC.
But for recent ones, you’ll have this option to switch to the UEFI BIOS.
Before starting with this guide, make sure:
- You have a full backup of your system
- You don’t have more than three partitions
- Device encryption services like BitLocker is turned off
And yeah, don’t bother reading any further if you’re on Windows 11. In that case, your PC should already be running on UEFI. However, this is an important item on the checklist for Windows 10 users who wish to upgrade to Windows 11.
Let’s start with the main course.
Check the current status.
Type System Information in the Search bar and click open the appropriate result.
There you can check the BIOS Mode is showing Legacy:
You can also confirm this with the disk type. Press Windows+R, type diskmgmt.msc, and click OK.
This will open the Disk Management console. Follow the steps in the given video and verify that you have Master Boot Record (MBR) in the Partition Style mentioned under the Volumes tab.
So now that we know we have an MBR disk, we will try to convert it to GPR. This is done with a simple tool, MBR2GPT, which Microsoft has shipped with Windows 10 version 1703 or later.
You can check your Windows version by typing <strong>winver</strong> in the Run (Windows+R).
As we are eligible to use that tool, let’s head towards the command prompt.
MBR to GPT Conversion
Open the command prompt with the administrator privileges. For this, type cmd, then click the Run as administrator in the right panel.
Afterward, enter mbr2gpt /validate /allowFullOS in the command prompt:
Check that the validation is successful. Go through this solution from the Microsoft community if you’re getting Disk layout validation failed.
After successful validation, type mbr2gpt /convert /allowFullOS and hit enter:
The Failed to update ReAgent.xml is an error specific to my system. You may not get it, and this won’t affect the conversion process even if it’s there.
Conclusively, the process is complete, and we’ve changed BIOS Mode from Legacy to UEFI.
And this screenshot confirms that:
Additionally, the disk management tools show the partition style is GUID Partition Table (GPT). This process created a 100 MB EFI partition from the main disk. You can validate this by noticing the change in the size of the main partition which was reduced from 458.35 GB to 458.25 GB.
But your computer won’t boot after this because the last step consists of changing the BIOS settings from Legacy to UEFI. As already stated, this depends on your PC manufacturer or on your motherboard brand if you’ve got an assembled PC.
Conclusion
While it was easy to convert BIOS mode from Legacy to UEFI in Windows 10, an average user may not need it. So make sure you really need to do this before going through all this trouble.
If it ain’t broke, don’t fix it!
Instead, what’s worth fixing are the hearts of countless people made ineligible from getting Windows 11. 😉
So check out Geekflare’s guide to install Windows 11 on unsupported PCs.