How to convert GPT to MBR

When installing the Windows operating system on a computer, some users are faced with the need to convert GPT to MBR. For example, in a situation where during the installation of the system a message appears that it is impossible to install the system on a hard disk with the GPT partition style. One solution to this problem is to convert the GPT partition table to MBR.

For a long time, computers used the master boot record – MBR (Master Boot Record). When the operating system boots, the BIOS initializes the computer devices, accesses the master boot record, and then transfers control to the operating system.

Modern hard drives default to the GPT partition style, which has replaced MBR. GPT (GUID Partition Table) – The GUID partition table is part of the UEFI (Unified Extensible Firmware Interface) interface, which is gradually replacing the outdated BIOS on computers. Read here how to find out the GPT or MBR disk installed on your computer.

Why is it necessary to convert a GPT disk to MBR

Over time, new technologies appear, so the usual BIOS has been replaced by UEFI, which implements the technology for initializing and transferring the boot of the Windows operating system in a different way. In particular, UEFI has Secure Boot.

Hard drive manufacturers began to produce products with a GPT table that support the new BIOS interface. GPT disks have some differences from MBR disks.

The main differences between GPT and MBR disks for normal users are:

• disks with MBR are limited in size up to 2 TB and in the number of partitions on the disk up to 4 partitions;
• GPT partitioned drives support 128 partitions and a much larger hard drive;
• you cannot install a 32-bit version of Windows on a GPT disk;
• GPT disks for Windows installation are used only with UEFI BIOS.

The user can decide on his own in which situations it would be preferable to use one or another hard disk partitioning option.

For example, you have a rather weak computer, so using 64-bit Windows instead of 32-bit does not make sense because you will not get any benefits, and in most cases, the x64 system will devour more system resources. To install or reinstall the operating system on an MBR disk, any bootable Windows USB flash drive will do. In the case of the GTP disk, there are some nuances due to which it will not be possible to boot from a USB flash drive and install the OS.

In this article, we are looking at how to change the style of GPT partitions to MBR master boot record. In other situations, on the contrary, you will need to convert the MBR to GPT .

In the instructions, I will tell you how to change GPT to MBR using the Windows operating system: using the Disk Management snap-in and the command line. You can change GPT to MBR using system tools only with the loss of data on the disk, including on all logical partitions of this disk.

There are ways to convert HDD from GPT to MBR without data loss. For this, third-party software (Acronis Disk Director, Paragon Hard Disk Manager, AOMEI Patition Assistant, EaseUS Partition Master, MiniTool Partition Wizard, etc.) is used, which is launched from the bootable media.

How to Convert GPT to MBR from Disk Management

Directly from the operating system, you can change GPT to MBR from the Disk Management snap-in. To do this, follow these steps:

1. Simultaneously press the keyboard keys “Win” + “R”.
2. In the “Run” window, in the “Open” field, enter the command: “diskmgmt.msc” (without quotes), click “OK”.
3. In the “Disk Management” window, right-click on the name of the disk, in the place where the names of local disks are located: “Disk 0”, “Disk 1”, etc.
4. If there is data on the disk, the “Convert to MBR Disk” context menu item will be inactive. To activate the conversion option, you must delete the data from the disk.
5. Right-click on the disk location, select “Delete volume …”.
6. After cleaning the disk, click on the disk name, select “Convert to MBR Disk”.
7. Take the necessary steps.

Once the GPT to MBR conversion is complete, you will have a hard drive that supports Master Boot Record (MBR). Now you can install Windows of any bitness on this disk.

How to convert GPT to MBR when installing windows on command line

The user can change GPT to MBR directly during the installation of the Windows operating system. We will convert GPT to MBR when installing Windows 10. Similar steps are performed in Windows7, Windows 8, Windows 8.1 operating systems.

During the installation of the operating system, an error message will appear in the window for selecting a partition for installing Windows: “Windows cannot be installed on partition X of drive X. (Show details)”.

After clicking on the link, a window will open that says: “Windows cannot be installed to this disk. The selected drive has the GTP partition style.”

There are three options for solving the problem:

• using a bootable Windows flash drive that supports installation in UEFI and GTP;
• deleting all partitions on the disk during Windows installation, when the installation continues, the system will automatically create a suitable partition style;
• during the installation of Windows, using the conversion from GPT, make an MBR disk (our case);

The command line will help us convert a disk from GPT to MBR.

In the Windows setup window, press the “Shift” + “F10” keys (on some laptops it may be “Shift” + “Fn” + “F10”).

A console will open in which you need to execute serial commands. After entering each command, press the “Enter” key.

Enter the command to run the Diskpart disk utility:

diskpart

The following command lists the drives:

list disk

Then you need to select the disk number from the list of physical disks on the computer where you want to install Windows. Your computer may have multiple hard drives. When choosing a disk, be guided by the size of the disk.

select disk X (X is disk number)

Now you need to clean up the disk. All disk partitions and data will be deleted.

clean

Enter the command to convert the disk to MBR format:

convert mbr

After the disk conversion is complete, enter the command to exit the Diskpart utility:

exit

Close the console window.

The disk has been converted to MBR, you can continue installing Windows.

In the operating system installation window, to select a disk, click on “Update”. The new location “Unallocated space on disk 0” appears.

Click “Create” and then the “Apply” button.

In the window that opens, you will see a message: “To ensure that all of its features work correctly, Windows may create additional partitions for system files.” Click on the “OK” button.

The operating system has created a special partition (“Reserved by the system”). Select another size (it is larger) to install the system, click on the “Next” button.

Windows installation starts. Read detailed articles about installing different versions of Windows.

Article Conclusions

If necessary, the user can convert the GPT disk partition scheme to MBR using the system tools: the Disk Management snap-in and the command line, which can be used to convert the disk when installing the Windows operating system on the computer.