Fix MBR or Operating System Not Found in Windows 7
By on March 15th, 2011

Back when I first started playing with different Linux distributions, like Ubuntu, I’d accidentally wipe out the boot loader. I had been through this scenario in Windows XP countless times and I knew how to restore the Windows master boot record.

win7-logoThis time, it happened to me in Windows 7. I was playing around with a Linux boot loader utility and I accidentally trashed the MBR (master boot record). I ended up with a really weird message when I went to restart the machine. It wasn’t Operating System Not Foundbut I knew what had happened.

Fortunately, I had created a Windows 7 Repair disk. If you haven’t done this yourself, take a few minutes and do it now.

Create a Windows 7 Repair Disk

  1. Insert a blank CD
  2. Click on the Start button and type repairinto the search box.
  3. Click on Create a System Repair Discand follow the instructions.

create-system-repair-disc

Repairing a missing or corrupted boot record

Let’s assume that you have either a Windows 7 Installation DVD or a repair disk. Here’s the scoop on how to fix a missing boot record, or some other weird boot error.

  1. Set your BIOS to use the CD/DVD drive as the primary boot device.
  2. Boot with your Windows 7 installation disk or the Windows Repair disk.
  3. Press a key when the message indicating “Press any key to boot from CD or DVD …” appears.
  4. (Skip to step 6 if using a repair disk) Select a language, a time and currency, and a keyboard or input method, and then click Next.
  5. Click Repair your computer.
  6. In the System Recovery Options dialog box, choose your installation and click Next.
  7. In the System Recovery Options dialog box, click Startup Repair.
  8. If step 7 fails, click the Command Prompt and enter the command bootrec.exe /fixmbr(without the quotes)
  9. Reboot the computer with your fingers crossed.

Below are the images for the steps above.

Step 6

windows7repairmbr_thumb

Step 7 or the beginning of Step 9

system-recovery-options

Step 9

fixmbr

If you have multiple partitions with different operating systems on them, this may not help you recover anything but Windows 7. Your best bet is to use a method to back up your boot settings before the inevitable problems occur. Another good safety measure is to completely back up your hard disk.

Even the smartest geeks mess up now and then. That’s how they learn. I’m hoping that your learning experiences don’t make you start swearing at the computer.

Tags: , ,
Author: Clif Sipe Google Profile for Clif Sipe
Promoting Freeware and Free information since 2004. Owner of FreewareWiki.com with over 2000 pages of freebies. Please subscribe to my Google Feed or follow me on Twitter @clifnotes.

Clif Sipe has written and can be contacted at clif@techie-buzz.com.
  • http://lusenji.wordpress.com Emmanuel – opensourceguy

    Thanks man! Your steps were straight forward. The /fixmbr command did it for me, after encountering a grub rescue message (i had deleted a partition containing ubuntu).

  • Bijan

    Hi
    My system only shows “operating system not found” and can not go further!
    Unfortunately, I didn’t build the Recovery DVDs before, so I borrowed my friend’s Recovery DVD to become able to start the system and go to recovery section.
    for your information, my laptop is “SONY VAIO VPC-F12FFX/B” and his model is “VPC-F111FX” that are very similar (but of course, their DVD can not use completely for another)

    The problem is that your step-by-step solutions seems to be OK (and its almost the same as Microsoft Solution Center and some other sites); but in this Algorithm, no one stated the point that our result is different than something that should appear there!

    <>

    Let’s return to my problem:
    In Step 6 , I should be able to see my missing operating system and of course, I should select it. But why nobody didn’t tell that if nothing shows, what should be our next step?

    Anyway, after doing some “try & error” ways, finally I become able to go to your 7 section titled “Select a recovery tool”
    As explained above, I couldn’t try “System Restore” (because Recovery DVD’s was not mine), and instead, I selected “Start up Repair” and followed its orders, but after restarting my computer, nothing solved :(

    I did it once again and then, I went into Command Prompt and tried “bootrec.exe” first with /fixmbr and then, with all of 3 other parameters (of course, I restarted my system after any changes)

    The only result is that my system error changed to:
    “BOOTMGR is missing”

    I know that there are special methods for solving this problem, but a very strange thing is that when I want to try the “System Restore” in “Select a recovery tool” section, windows will do some show-off and then says:
    “Startup Repair cannot repair this computer automatically”
    and wants me to “Send information to Microsoft”!

    for your information, problem details, as it says, are:
    Problem Event Name: StartupRepairOffline
    Problem Signature 01: 6.1.7600.16385
    Problem Signature 02: 6.1.7600.16385
    Problem Signature 03: Unknown
    Problem Signature 04: -1
    Problem Signature 05: ExternalMedia
    Problem Signature 06: 1
    Problem Signature 07: MissingBootManager
    OS Version: 6.1.7600.2.0.0.256.1
    Locale ID: 1033

    My question is that, If we should try again the triple magic
    “bootrec /RebuildBcd” ,
    “bootrec /FixMbr” and
    “bootrec /FixBoot”,
    why the Microsoft “Startup Repair” program was not able to knew that?

    Oh! I tried of typing, I don’t know what happened to your mind :)

  • http://josh-wood.weebly.com Josh Wood

    At step 6 it doesn’t find my windows 7 installation

  • angelobeltran

    What happens then if you have no os listed under STEP 6?

 
Copyright 2006-2012 Techie Buzz. All Rights Reserved. Our content may not be reproduced on other websites. Content Delivery by MaxCDN