What is a Master Boot Record?

Malcolm Tatum

The master boot record, or MBR, is a section of the storage space on a hard disk drive that is used for the maintenance of data needed to initiate a boot of the computer. Generally, the boot record is housed in the very first sector of the hard drive, making it easy for the system to locate, read, and execute the files necessary to launch the application. All the codes needed to access the files, and begin the boot are included in the master boot record.

A master boot record is stored within the hard disk drive of an electronic device.
A master boot record is stored within the hard disk drive of an electronic device.

There are several key elements of a MBR that allow the section to function at optimum efficiency. One of the more important elements is the partition table. This table contains the basic directory that guides the process of reading and initiating the boot. The partition table will work in conjunction with some type of bootloading software in order to interact with the operating system and successfully complete the process.

As with all sections of the hard drive, it is possible for the master boot record to become corrupted. When this happens, it may be impossible to boot up the hard drive at all. However, if the master boot record is still partially operational, there is some chance of being able to launch the operating system in safe mode. From there, it may be possible to restore the hard drive to an earlier condition using recovery software that is housed on the hard drive. If the drive will not boot up at all, it may be possible to correct the problem by using the recovery disk that manufacturers normally provide as part of the support resources that come with the computer hard drive.

If the user is unable to work around the corrupted state of the master boot record, the hard drive may need to be analyzed and repaired by a professional. This may involve extracting saved data from the hard drive and rebuilding the partition table in order to salvage the drive. Many hard drives can be salvaged and the saved data reloaded in a short period of time.

Malcolm Tatum
Malcolm Tatum

After many years in the teleconferencing industry, Michael decided to embrace his passion for trivia, research, and writing by becoming a full-time freelance writer. Since then, he has contributed articles to a variety of print and online publications, including EasyTechJunkie, and his work has also appeared in poetry collections, devotional anthologies, and several newspapers. Malcolm’s other interests include collecting vinyl records, minor league baseball, and cycling.

You might also Like

Discussion Comments


@JaneAir - I don't blame you for being worried! Hard disk problems can sometimes mean the end for a computer.

Fortunately though, there are ways to recover data from a corrupted hard drive. Sometimes this results in a fix for the computer, and sometimes it just results in the user being able to recover some of their files to put on their next machine.

Although sometimes the computer can't be fixed and the data is all lost. That is a bitter pill to swallow, let me tell you. Especially when you forgot to back up your data!


I once almost lost a computer to master boot record damage. My computer would start to boot up, and then it would just stop. It was like the computer just didn't know what to do after a certain point!

I was actually afraid the problem was so bad I was going to have to get another computer. I took it to my local computer repair shop and they were able to fix it, luckily. I'm not exactly sure what they did, but they did mention the master boot record quite a lot.

After that little fiasco I used that computer for about another year before I upgraded. I actually tried booting it up a few weeks ago to see if it still worked, and it does!


anon21212, please consider submitting your four queries via the "Suggest a Topic" option located under wiseGEEK features at the top of the page.


1. What is file integrity mechanism.

2. How can i represent a file with variable length and a block record with a diagraph.

3. How to compute storage capacity.

4. What are the latest optical disk.

Post your comments
Forgot password?