By AOMEI / Last Updated December 3, 2019

Need to convert GPT to MBR during windows install? Let’s take a look at what are GPT and MBR first.


GPT (GUID Partition Table) disks use unified extensible firmware interface (UEFI). GPT can make use of a very large space that is more than 2TB limit of MBR disks. GPT disks allow an almost unlimited number of partitions. Each GPT partition has a unique identification GUID and a partition content type. And you can have more primary partitions.

MBR (Master Boot Record) disks use the standard BIOS partition table. MBR disks do not support more than four primary partitions on each disk. The MBR partition method is not recommended for disks larger than 2 terabytes. If partition size surpasses 2TB, the surpassed part cannot be used.

Why convert GPT to MBR?

From above description, it seems that GPT disk is much better than MBR. Why should we bother to convert GPT to MBR? Before answering this question, I want to ask: when installing Windows on BIOS-based PCs using Windows Setup, have you receive the error message: “Windows cannot be installed to this disk. The selected disk is of the GPT partition style”?

Actually, some of personal computer's motherboard only supports BIOS and it is installed with MBR, so, for many users, they always install windows system on the MBR disk. Some of computers do not have EFI motherboard, many people can’t install Windows system on GPT disk. Your PC is booted in BIOS mode, but your hard drive is not configured for BIOS mode. That’s why you need to convert GPT to MBR Windows 7 install.

Error Message

How to convert GPT to MBR during Windows 7 install?

Basically, there are two ways to convert GPT to MBR.

Method 1: Convert GPT into MBR during Windows 7 install with dispart

Step 1. Open command prompt window during installation by pressing Shift + F10.

Command Prompt

Step 2. Input “diskpart”, and then press “Enter” to enter the operating interface. Next input “list disk”: to check hard disk properties, and then press “Enter”.list

List Disk

Step 3. Now type “select disk 2”. By using this command, you select the disk number you need to convert to MBR.

Select Disk Number

Step 4. Input “clean” to clean up the current disk's partition, and then press Enter.

Warning: Thie command will erase all data on the selected disk.

Step 5. Input “convert mbr” to convert GPT into MBR.

Step 6. When it completes, you can exit Diskpart and then go back to install Windows 7.

This method seems very concise. However, it has a big shortage, that is all data and files will be clean up. If you do not back up the GPT disk, then all the data on that disk are lost. If you do not want to lose all your valuable files, you can use method 2 to convert GPT disk to MBR without data loss.

Method 2: Convert GPT to MBR during Windows 7 install without data loss

Step 1. Insert a CD or a USB flash drive to another working computer running Windows 10/8/7; install and launch AOMEI Partition Assistant Professional. Click on “Make Bootable Media” and follow the wizard to finish creating a bootable media.

Make Bootable Media

Step 2. Insert this bootable disk to the computer that you're having problem installing Windows on, and then choose CD-ROW Drive to boot from the bootable media.

CD ROW Drive

Step 3. When the interface of AOMEI Partition Assistant Professional is loaded, right-click disk 1 and choose Convert to MBR Disk.

Convert System Disk To Mbr

Step 4. Click OK to make sure convert GPT to MBR. At last, click Apply to save the operation.

Apply To Mbr System Disk


AOMEI Partition Assistant Professional is a powerful software for partition management. It allows users to convert GPT to MBR during Windows 7 install without data loss and deleting partitions. Also, you can use it to convert FAT32 to NTFS without losing data, clone HDD to SSD and so on. Of course, if data loss is not an issue, you can convert GPT to MBR with Diskpart.