Fix MBR
"I was trying to fix a spyware problem and it seems I messed up my computer. Now when I start Windows XP, I get the 'MBR Corrupt' and 'Error loading operating system' messages. What should I do?" |
Got a Damaged Master Boot Record?
Although those messages sound pretty scary, there's a good chance your hard drive is still intact. In most cases this problem can be fixed with a simple procedure that repairs your Master Boot Record (MBR). When you start your computer, the BIOS (basic input/output system) looks for the MBR on the first sector of your hard drive. The MBR tells the BIOS which partition on the hard drive contains the operating system.
So... if the MBR is damaged, the BIOS can't locate and start the operating system. When your BIOS detects a damaged MBR or boot sector, you'll see ominous messages like Invalid partition table, Error loading operating system, or Missing operating system. In some cases, dark clouds will apppear on the horizon, and you may hear the distant rumble of thunder. But fortunately, the Recovery Console offers some tools to help clear up the problem.
Repairing a Damaged MBR
Your Windows XP setup CDROM has a tool called the Recovery Console, which is designed to help you repair a damaged master boot record or boot sector. To start the Recovery Console and fix your damaged MBR, follow these steps:
- Restart your computer with the Windows XP Setup disk in the CDROM drive.
- If you are prompted to press a key to start the computer from CDROM, do so quickly. Otherwise it may try to boot from the hard drive.
- After a few minutes, you'll see a prompt to press the R key to start the Recovery Console.
- When Recovery Console starts, it will prompt you to enter a number corresponding to the Windows XP installation that you need to repair. In most cases, you'll enter "1" (which will be the only choice). If you press ENTER without typing a number, Recovery Console will quit and restart your computer.
- Enter your Administrator password. If you don't enter the correct password, you cannot continue.
- At the Recovery Console command prompt, type fixmbr and then verify that you want to proceed.
Your damaged MBR will be replaced with a shiny new one, and you should then be able to boot your system normally. In some cases, you may need to repair the boot sector in addition to the MBR. If your system still doesn't boot properly, repeat the steps above, but issue the fixboot command instead.
NOTE: These procedures assume that you have only one operating system installed. If you are an advanced user and have a multi-boot system with more than one operating system, you may need to do some additional reading about the fixmbr and fixboot commands at the Microsoft website.
Do you have experience with a damaged master boot record? Post your comments below...
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Posted by Bob Rankin on 7 Jun 2006
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Article information: AskBobRankin -- Fix MBR (Posted: 7 Jun 2006)
Source: http://askbobrankin.com/fix_mbr.html
Copyright © 2005 - Bob Rankin - All Rights Reserved
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Most recent comments on "Fix MBR"
(See all 115 comments for this article.)Posted by:
Earl
29 Nov 2010
Fixed the MBR many, many times. Well the XP Recovery Disk hangs at the "repair" or "re-install" or "quit" screen. Re-booted like 100 times freezes at that screen every time no key does anything. Any suggestions?
Posted by:
shubham
18 Jan 2011
i tried to fix mbr using recovery console and it said that it fixed but on rebooting again black screen comes.
please help me out
Posted by:
Marc Hall
01 Feb 2011
What if the HDD is connected via USB?
Posted by:
alain63720
02 Feb 2011
Hello
What do you do when you have a black screen???
Alain
Posted by:
Tory
17 May 2011
worked like butter! Thanks so much...you saved me a bunch of heartache.
Posted by:
steven
24 Jun 2011
Why do both you and Ask Leo keep mentioning a windows CD/DVD? All people gerare a recovery partition and have to burn a recovery disk. My house went through 4 computers aand none of them came with a real windows disk. Nobody bought windows, either
Posted by:
loanstk
26 Jun 2011
I am trying to get to the repair screen, I have the blue screen that comes up with unmountable Boot volume. When the system boots up it acts like it is loading Windows xp but then the blue screen comes up everytime. I am hitting, f12, f8, none of these options is helping. I dont see the repair screen at all. I am also trying to reboot with the disk and the same thing comes up as well, there is no repair option or the dos format to have me enter in the codes suggested. chkdsk/r or fixboot. Does this mean my Hard Drive is not able to be fixed? again there is no option at all for repair option at all while loading the XP disk. Thanks for your suggestions.
Posted by:
tawee
22 Sep 2011
have dual boot system, one for xp the other for vista, with xp is the primary boot.
Lately, I installed the power quest; partition resizer on the vista to extend the size, no complaint about the installation.
But, when I started the pqpr, a shot pop-up message asked me to correct the conflict in the vista partition.
I pressed y, and restarted the system, so far, the blue screen complained with proposing to use chkdsk /f to resolve the problem.
I then used "PTTD partition table doctor" to solve which reported the total sectors of 68356538,
with actual sectors of 68356575, the difference of the last 2 digits. The PTTD does nothing to solve the overlapping partition.
In xp which is still bootable, can see the vista as another drive.
Your help please!!!
BTW: Is it posible to copy patition table from xp to vista?, as xp works well, but vista has problem of partition size incorrect.
Posted by:
Willie
02 Nov 2011
If you are stuck with the XP Password bug, (like I was) just use a Windows 98 CD or DOS boot disk. Once you boot to DOS, use
FDISK /MBR
Remove the CD or floppy, reboot and see XP resurrected! :)
Posted by:
Dennis
15 Nov 2011
@Willie
Great suggestion and a save I've used lots of times Willie!
If you don't have a copy of the venerable but still hugely useful DOS operating system available get one from http://www.freedos.org/
Load it on a flash drive or ISO copy to a CD; if necessary, adjust your BIOS to boot from that media first, and Away You Go!
One caveat, if you are running a dual or multi-boot system and are using an alternative boot loader such as GRUB you will have some additional jiggery-pokery to do, but you already know how to do that!