On Windows 10, you can use the MBR2GPT command-line tool to convert a drive using a Master Boot Record (MBR) in the GUID Partition Table (GPT) partition style, which allows you to correctly switch between Basic Input / Output System ( BIOS) to the Unified Extensible Firmware Interface (UEFI) without changing the current installation and without having to delete the data stored on the unit.
Simply put, using a small tool built into Windows 10 called MBR2GPT, we can quickly convert the type of disk partition from MBR to GPT . This change favors the transition from BIOS to UEFI, which is simpler to use and also more useful. While before this operation required a new installation of Windows 10, now, thanks to this tool, everything remains as it is and nothing is deleted on the converted disk.
Regarding what the BIOS does, as already written in a specific guide, just know that it is an essential program of each computer that is loaded by a special chip on the motherboard and which is used to connect the hardware and software. The BIOS has existed for many years, it is still widely used, but it has many limitations such as the inability to manage partitions with space greater than 2 TB.
READ ALSO: MBR or GPT disk "> Secure Boot" to protect the computer boot process from malware, the "Device Guard" to control access to apps and "Credential Guard" can help prevent unauthorized access attacks computer data.
To use UEFI on every modern PC with Windows 10 64Bit (32 bit versions are excluded) and therefore to have a faster, more stable and safer system, you need to convert the disk drive from the MBR style to GPT, which has become easy to do and without danger.
Before changing the system configuration, you can check whether the system is set to MBR or GPT with these steps:
NOTE: Before changing the style of the partition, it is better to check the support website of the computer or motherboard manufacturer to find out if the hardware includes support for UEFI (if it is a recent model it definitely supports it, otherwise it is better to check well ).
mbr2gpt / validate
If after this command a message appears like " Disk layout validation failed for disk 0 ", then the conversion cannot be done (see below on possible problems)
The mbr2gpt.exe command is located in the "System32" folder inside the "Windows" folder. If you want to see all the available options, use the mbr2gpt /? Command . .
Now, to convert the unit from MBR to GPT, write the command and press Enter:
mbr2gpt / convert
Once done, press the button to close in the upper right corner of the console and turn off the computer.
After completing the steps, several actions will occur, including validating the drive and creating an EFI system partition (ESP). The UEFI boot files and GPT components will be added to the partition, then the MBR2GPT tool will update the boot configuration data (BCD) and the previous letter will be added to the drive.
To convert an MBR to GPT drive on Windows 10, open the Start menu and look for the command prompt. Right-click on the prompt to run it as an administrator.
Type the following command to validate the drive and press Enter:
mbr2gpt / validate / allowFullOS
To convert the unit from MBR to GPT, write and run:
mbr2gpt / convert / allowFullOS
Once the steps are complete, the tool will try to shrink the main partition and switch it from MBR to GPT.
Using this tool, you cannot convert drives running Windows 8.1 or Windows 7, only Windows 10.
When using a drive that uses file encryption with BitLocker, encryption must be stopped before proceeding with the conversion.
Finally, while drives that use the MBR style can have up to four primary partitions, the drive you want to convert cannot have more than three partitions, since additional allocation is required to create the UEFI system partition.
If there are two recovery partitions that were created by upgrading to Windows 10 from Windows 7 or 8, you must delete at least one to proceed with the conversion from MBR to GPT. This can be easily done with a partition management program such as AOMEI Partition Assistant.
When you turn on the PC, you must then press the key to access the BIOS, usually one of the function keys (F1, F2, F3, F10 or F12) or the ESC key or the Del key, depending on the manufacturer of the PC or motherboard.
In the firmware interface, find the " Start " or Boot menu and enable the UEFI option. Save the changes and the device should boot correctly.
The last thing to do is to check if the device is using the UEFI firmware mode.
READ ALSO: How to access UEFI on new PCs and how it changes from the BIOS
Simply put, using a small tool built into Windows 10 called MBR2GPT, we can quickly convert the type of disk partition from MBR to GPT . This change favors the transition from BIOS to UEFI, which is simpler to use and also more useful. While before this operation required a new installation of Windows 10, now, thanks to this tool, everything remains as it is and nothing is deleted on the converted disk.
Regarding what the BIOS does, as already written in a specific guide, just know that it is an essential program of each computer that is loaded by a special chip on the motherboard and which is used to connect the hardware and software. The BIOS has existed for many years, it is still widely used, but it has many limitations such as the inability to manage partitions with space greater than 2 TB.
READ ALSO: MBR or GPT disk "> Secure Boot" to protect the computer boot process from malware, the "Device Guard" to control access to apps and "Credential Guard" can help prevent unauthorized access attacks computer data.
To use UEFI on every modern PC with Windows 10 64Bit (32 bit versions are excluded) and therefore to have a faster, more stable and safer system, you need to convert the disk drive from the MBR style to GPT, which has become easy to do and without danger.
- How to convert an MBR to GPT disk on Windows 10
- How to change the firmware mode from BIOS to UEFI
How to convert an MBR to GPT disk on Windows 10
To do this delicate operation on the PC disk, a full data backup and a reinstallation of Windows from scratch was required up to a year ago. Now the MBR2GPT command line tool simplifies this process and allows you to change the style of partitions in minutes. The conversion is done by adding the GPT components to the MBR partition, without changing the existing partition and keeping the data unchanged.Verify the style of the MBR or GPT partition
Keep in mind that usually, when installing Windows 10 from scratch, the choice should be to start in UEFI mode. However, if you have upgraded from Windows 8.1 or Windows 7 to Windows 10 or if you have installed Windows 10 on a PC set on the traditional BIOS, then you need to convert the unit to correctly change the system firmware settings from the BIOS to UEFI.Before changing the system configuration, you can check whether the system is set to MBR or GPT with these steps:
- Right click on the Start menu and choose Disk Management .
- In Disk Management, right click on the box with Disk 0 (or the disk where Windows 10 is installed) and select the Properties option.
- Go to the Volumes tab and see if the partition style is MBR or GPT . If it is GPT, go to step 2 of this guide, otherwise proceed with the conversion.
- Press Cancel .
NOTE: Before changing the style of the partition, it is better to check the support website of the computer or motherboard manufacturer to find out if the hardware includes support for UEFI (if it is a recent model it definitely supports it, otherwise it is better to check well ).
Converting the MBR Partition Style to GPT (Recommended)
To convert a unit using MBR to GPT on Windows 10, follow the steps below:- Open Settings
- Go to Update and Security .
- Go to Restore .
- Press the Restart Now button under the " Advanced startup " section.
- On reboot, click Troubleshoot
- Click on Advanced Options .
- Click on Command Prompt .
- Then select the administrator account and log in.
mbr2gpt / validate
If after this command a message appears like " Disk layout validation failed for disk 0 ", then the conversion cannot be done (see below on possible problems)
The mbr2gpt.exe command is located in the "System32" folder inside the "Windows" folder. If you want to see all the available options, use the mbr2gpt /? Command . .
Now, to convert the unit from MBR to GPT, write the command and press Enter:
mbr2gpt / convert
Once done, press the button to close in the upper right corner of the console and turn off the computer.
After completing the steps, several actions will occur, including validating the drive and creating an EFI system partition (ESP). The UEFI boot files and GPT components will be added to the partition, then the MBR2GPT tool will update the boot configuration data (BCD) and the previous letter will be added to the drive.
Convert MBR to GPT from the Windows 10 desktop
The MBR2GPT tool was designed to work offline in the recovery environment, but it can also be used when Windows 10 is fully loaded, although it is not recommended.To convert an MBR to GPT drive on Windows 10, open the Start menu and look for the command prompt. Right-click on the prompt to run it as an administrator.
Type the following command to validate the drive and press Enter:
mbr2gpt / validate / allowFullOS
To convert the unit from MBR to GPT, write and run:
mbr2gpt / convert / allowFullOS
Once the steps are complete, the tool will try to shrink the main partition and switch it from MBR to GPT.
Return codes MBR2GPT
When running the conversion command, the return code must be 0 if all went well. In the case of errors, a different number appears depending on the type of error. The list of codes and errors is as follows:- 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 is 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 and possible problems
The MBR2GPT command line tool works to convert a traditional hard drive (HDD), a solid state drive (SSD) and even an M.2 drive with any version of Windows 10, but you need to run the tool from a computer running Windows 10 version 1703 or later (version 1809 recommended).Using this tool, you cannot convert drives running Windows 8.1 or Windows 7, only Windows 10.
When using a drive that uses file encryption with BitLocker, encryption must be stopped before proceeding with the conversion.
Finally, while drives that use the MBR style can have up to four primary partitions, the drive you want to convert cannot have more than three partitions, since additional allocation is required to create the UEFI system partition.
If there are two recovery partitions that were created by upgrading to Windows 10 from Windows 7 or 8, you must delete at least one to proceed with the conversion from MBR to GPT. This can be easily done with a partition management program such as AOMEI Partition Assistant.
How to change the firmware mode from BIOS to UEFI
After converting the drive using a GPT partition style, the device will no longer boot properly until you access the motherboard firmware to switch from BIOS to UEFI.When you turn on the PC, you must then press the key to access the BIOS, usually one of the function keys (F1, F2, F3, F10 or F12) or the ESC key or the Del key, depending on the manufacturer of the PC or motherboard.
In the firmware interface, find the " Start " or Boot menu and enable the UEFI option. Save the changes and the device should boot correctly.
Checking the style of the GPT partition
To verify that the computer is using the GPT partition style, right-click on the Start menu to open Disk Management, then right-click on Disk 0 or Disk 1 (the one where Windows 10 is installed), go to the Volumes section and check that the partition style is the GUID Partition Table (GPT) .The last thing to do is to check if the device is using the UEFI firmware mode.
Verification of the UEFI firmware
To verify that the computer is using UEFI firmware mode, open the Start menu and search for msinfo32 . Then open the System Information utility and in the System Resources summary tab, look for the BIOS mode which should no longer be Legacy, but UEFI .READ ALSO: How to access UEFI on new PCs and how it changes from the BIOS
