Set Up the Boot Mode in MBR for BIOS, Legacy or UEFI - EaseUS

In setting up a computer, configuring the correct boot mode for your OS drive is essential. 

While installing Windows, if you receive the error message: "Windows cannot be installed to the disk. The selected disk is not of the GPT partition style", it means your PC is booted in UEFI mode, but your hard drive is not configured for UEFI mode.

Here is the right way to get rid of this problem:

Let's get started here.

 #1. Confirm If Computer Is Shipped with BIOS or UEFI Firmware

To configure the right boot mode for your operating system, it's important you first learn the two boot modes in Windows - BIOS (Legacy) and UEFI. So what is UEFI, and what are the differences between UEFI and BIOS? 

To get started, let's first learn the difference between BIOS and UEFI first:

Intel has announced plans to completely replace BIOS with EUFI on all their chipsets by 2020.

If your Windows computers are shipped with Intel chips after 2020, all of them will require UEFI boot mode.

But, if your computer is older than this and was shipped before 2020, how can you tell if your computer is BIOS or UEFI? Here are the steps that you can follow to figure out the boot mode in your computer firmware:

Option 1: Use System Information to Check If Your PC Used BIOS or UEFI

Step 1. Open Start, type system information in the search box, and click to open it.

Step 2. Find the BIOS Mode under System Summary.

• If it says Legacy, your device is using BIOS.
• If it says UEFI, your PC is running with UEFI.

Option 2. Use setupact.log to Check If Your PC Uses BIOS or UEFI

Step 1. Open File Explorer, and go to the following path:

LocalDisk(c:)/Windows/Panther.

Step 2. Find and open the setupact.log file in Notepad.

Step 3. Locate the Detected Boot Environment, and there, you'll be able to check if your device is using BIOS or UEFI.

#2. Check If Your Windows Is MBR or GPT

So how to tell if your Windows OS drive is with MBR or GPT? Here is a quick guide that you can follow to check:

Step 1. Open Disk Management, right-click on the Disk 0, and select "Properties".

Replace 0 with the correct disk number of your Windows drive.

Step 2. Click the Volumes tab, then check the listed format next to Partition style.

You'll see the partition style - Master Boot Record (MBR) or GUID Partition Table (GPT).

Now, you've known your computer's boot mode and disk partition style. Continue with the guide in the next part, and you'll learn how to set up the right mode in MBR for BIOS?

If you are looking for a reliable tool that works to convert disk between MBR and GPT without losing any data, EaseUS Partition Master is capable of help.

#3. Set Up Right Boot Mode in MBR for BIOS - Legacy or UEFI

To configure the right mode for your Windows disk, it's essential that you master some basic tips here:

• MBR is configured with BIOS Legacy Boot Mode.
• GPT is set up with UEFI Boot Mode.

So when to use MBR and when to use GPT disk? First, let's simplify the rule:

• Disks with 2TB or smaller capacity, you can set up the disk with MBR partition style.
• Disks with 3TB or even bigger sizes, set it up with GPT style.

Suppose that your OS drive is now 2TB or smaller, and it's now with MBR partition style. What boot mode is right for MBR? Yes, it's BIOS Legacy.

Here is the process that you can follow to set up the right boot mode in MBR for BIOS: 

Step 1. Reboot the PC and press F2/F8/F11 or Del to enter the BIOS menu.

Step 2. Go to the Boot tab, select the Boot Mode, and use the up and down arrows key to select Legacy BIOS Boot Mode. Press Enter to confirm.

Step 3. Press F10 to save the changes and exit BIOS.

After this, you'll need to wait for the computer to reboot. When the process completes, Windows will be able to boot up successfully on your MBR disk.

If you are about to change your OS disk to GPT or migrate OS to a bigger GPT HDD/SSD, remember to follow the steps above to change the BIOS mode from Legacy to UEFI.