Knowledge of MBR
MBR, short for Master Boot Record. It will be created when you create the first partition on the hard drive. It is very important data structure on the disk. The MBR contains the Partition Table for the disk and a small amount of executable code for the boot start. The location is always the first sector on the disk. Without a valid MBR, it’s impossible to boot the system from the hard disk.
If the MBR has something wrong, it may prevent the system from booting. The MBR may be affected by malicious code, become corrupted by disk errors, or be overwritten by other boot loaders when experimenting with multiple operating systems on a host. Viruses and programs gone haywire damage MBR usually.
If all of a sudden your computer does not boot and you see error information such as "operating system not found", "missing operating system" or "invalid partition table", you know there is something really wrong with the MBR. What cause corrupted MBR? Maybe your partition infected by trojan horse virus and your anti-virus program didn't remove it completely. Or maybe you loaded a backup image for one of the operating systems and this ended up slightly messing up the MBR. Some external hard disk may also encounter corrupted MBR.
How to Fix Corrupted MBR?
How to repair corrupted MBR due to a virus or some kind of damage?
If you OS is Windows XP, it can be fixed by using fix MBR command, following are details:
- Enter Windows XP Recovery Console.
- When you reach the command prompt, type "fixmbr" and then press Enter.
- The fixmbr utility will write a master boot record to the hard drive that you're currently using to boot into Windows XP. This will repair any corruption or damage that the master boot record may have.
- Take out the Windows XP CD, type “exit” and then press Enter to restart your PC.
Assuming that a corrupt master boot record was your only issue, Windows XP should now start normally.
In Windows 7 and Windows Vista, type the following command at the Recovery Console prompt:
BOOTREC/FIXMBR then press Enter.
Using Windows Recovery Console to repair corrupted MBR is a traditional way. Recovery is entirely possible if you can access the Recovery Console and you know which command to type for your version of Windows.
Repair Corrupted MBR with AOMEI Partition Assistant
Another situation, after the damage has occurred, the system was unbootable. The system would try to boot to a nonexistent copy of System Commander. Unfortunately, it was impossible to reinstall System Commander, because the system was unavailable. Now you need to employ AOMEI Partition Assistant Bootable USB or CD to resolve boot problem which has the same operation with AOMEI Partition Assistant. Next please see the following step-by-step instructions to fix corrupted MBR with its function - "Rebuild MBR".
- Connect the damaged computer’s hard drive to another PC as slave.
- Download AOMEI Partition Assistant Standard Edition in health PC, install and run.
- Click Rebuild MBR from the left panel or select the target disk then right click to choose Rebuild MBR. (see picture below)
- Set up the type of MBR to rebuild in the pop-up window. AOMEI Partition Assistant provides OS includes: Windows 7/8, Windows 2000/2003/XP, Windows Vista/Windows 2008. And then the program will set the type of MBR for your OS. (Choose a proper MBR type according to your operating system)
- At last, click "Apply" button to execute pending operation. Connect the fixed hard drive to original computer and boot from it when fixing MBR has completed.
Nowadays, many disks are GPT style, compare to MBR, GPT has many advantages, the most important one is that it supports partition larger than 2TB. If you want to try GPT, you can also use AOMEI PArtition Assistant with its function - "Convert MBR to GPT disk".