MBR is the abbreviation for Master Boot Record which is a special boot sector in the beginning of the hard drive. That is to say, it is created on the first partition on the disk. MBR describes the information of logical partition, including file system and organization mode. In addition, it contains three parts which are boot loader, DPT (Disk Partition table) and magic number. Thereinto, the first part owns 446 bytes, DPT has 64 bytes, and magic number contains 2 bytes. MBR does not belong to any operating system. And it can’t be read by using disk operation command but it is able to be modified and rewritten.
Your computer may suddenly can’t boot and you will get such errors, “Error loading operating system”, “Operating System not found”, “Operating System missing” and “Invalid partition table”. If you encounter one of these cases, it is possible that there is something wrong in MBR.
Here is an example:
“I used a computer in Windows 8. But accidently power failure happened. I restarted my computer but it can’t boot. I received a message like “Invalid partition table”. I searched in Google and found it is because of MBR corruption. But I have no Windows 8 installation disk, so I don’t know how to fix MBR in Windows 8. Is there any suggestion? Thank you!”
Generally, MBR is corrupted in the following two situations:
1. Virus attack: if your system boot registry is attacked by virus, the MBR may be corrupted.
2. Accident power failure: if power failure accidentally occurs, the hard drive stops working which can cause MBR corruption.
After knowing the reasons of MBR corruption, it is time to fix this error.
In Windows 10/8/7, if your computer is unable to boot, there are two ways to repair MBR and boot system. You can use Windows 10/8/7 installation disk to repair the computer. During the process, open command window to input corresponding prompt according to different operating systems. To some degree, this way is a little difficult and the command prompt is different in Windows 7 and Windows XP.
Fortunately, a third-party professional partition and disk manager is very useful to fix MBR when system is unbootable. MiniTool Partition Wizard Bootable CD Free Edition is your good choice for MBR repair without any damage to data in Windows 10/8/7/XP/Vista. Firstly you need to download the ISO file of this free MBR repair tool and then burn it to a CD/DVD or USB device. This article How to Build Free Bootable Partition Manager with Pwfree91.iso can help you.
Step 1: Please connect the CD/DVD or USB flash drive to your computer and then boot your computer in BIOS. You need to modify the boot order and set it to boot from the CD/DVD or USB device.
Step 2: Then you will get the following interface.
Step 3: After finishing boot successfully, you can enter into MiniTool Partition Wizard main interface. Please right click the target disk and select “Rebuild MBR” or select this function from “Operations”.
Step 4: Finally, click “Apply” to perform this operation.
In conclusion, it is very easy to fix MBR with MiniTool Partition Wizard Bootable CD when computer is unbootable. If you are experiencing this problem, please try to use this freeware. Download now.