Master boot record

master boot record

MBR or Master Boot Record is a special type of boot sector that holds the information regarding partitions with file systems on them. MBR also works as a loader for the installed operating system, and it’s used to boot your operating system.

What is MBR, and how does it work?

How does MBR work?

When you turn on your PC, it will perform certain hardware tests, and if the hardware is in order, it will search for bootable drive and MBR. If the MBR is found, a small program in MBR will try to locate the active, also known as bootable, partition in the hard drive partition table.

Now the small program in the boot sector will locate the first part of the operating system’s kernel loader program, or the boot manager program and read that into memory. After doing that, your operating system should start booting.


Frequently asked questions regarding MBR

Where is the Master Boot Record?

Master Boot Record is located on the first sector of a hard disk drive or other storage devices.


What does the Master Boot Record do?

Master Boot Record identifies where the operating system is located on a storage device. Once the operating system is found, the MBR will load the operating system into the memory.


How do I know if my system is MBR or GPT?

To check if your hard drive is using MBR or GPT, do the following:

  1. Open This PC, locate the desired drive, right-click it and choose Properties from the menu.
    partition properties master boor record
  2. Go to the Hardware tab and double-click your system drive.
    partition properties windows master boot record
  3. Go to the Volumes tab and click Populate. Now check the Partition style information value.
    partition style master boot record

Alternatively, you can use Command Prompt or PowerShell to view this information:

  1. Press Windows Key + X and select Windows PowerShell (Admin) from the list.
    win + x menu master boot records
  2. Run the following commands:
    • diskpart
    • list disk
  3. You’ll now see a list of all drives connected to your PC.
  4. Look for the Gpt column. If it has an asterisk symbol, it means that it’s using GPT. If the asterisk symbol is missing, it means your drive is using MBR.
    diskpart master boot record

What does the Master Boot Record contain?

MBR holds information regarding the organization of the partitions with file systems. It also has a small code that loads the installed operating system.