Boot mgr cannot be found in laptop


Jan 22, 2010
I turned on my laptop then I switched it to sleep mode for 5 mins and so when I came back I turned it on then it said something about O.S. cannot be found and sometimes it says error reading disk then I tried reformatting it but to no help it said then boot mgr cannot be found. What is happening? pls help!
Hi newcomer and welcome to the Tom's hardware forum.

Try this:

Open "System Recovery Options" on the repair disk, or OS disk.
Open up the Command Prompt.Try typing the following commands in order:

1- bootrec /fixmbr and hit enter
2- bootrec /fixboot and hit enter
3- bootrec /rebuildbdc and hit enter

Reboot you PC and try to boot again.


Jan 22, 2010
hello saint 19! thank you so much for your help. I will try that and I'll get back to you if it works. But you mentioned OS disk, well another problem is I don't have it with me, I lost it, so is there any possible way to fix my laptop without the OS disk? Or is it really necessary? How can I fix this problem without using a disc? thanks.
Sounds like a failing hard drive... you'll know for sure when you can get a copy of the OS disc for further troubleshooting. At the very least, you have a few bad sectors and in my experience, it's better to replace the drive than to continue to rely on it.


I afraid that it is not possible without OS disk.
You can borrow it form your friend or neighbors and can do. (But of same version 32/64 & Basic/home premium/Ultimate etc).

Follow the procedure below:

- Get your Vista DVD and pop it into your drive.
- Then restart your computer.
- Set your computer to boot from DVD or CD in your BIOS.

Vista will ask you for language and keyboard layout information, after which you will be asked if you want to re-install Vista or repair your existing installation.
After that select Repair. After which Vista's System Recovery Tool will start.


If the previous method does not resolve the problem, you can rebuild the BCD store by using the Bootrec.exe tool in the Windows Recovery Environment. To do this, follow these steps:

- Get your Vista installation DVD and pop it into your drive.
- Then restart your computer.
- Press a key when you are prompted.
- Select a language, a time, a currency, and a keyboard or another input method, and then hit Next
- Click Repair your computer
- Click the operating system that you want to repair, and then click Next
- In the System Recovery Options dialog box, click Command Prompt
- Type bootrec /rebuildbcd and then press "Enter" key.

• If Bootrec runs successfully, it will present you with the installation path of a Windows directory. To add the entry to the BCD store, type Yes . A confirmation message appears that indicates the entry was added successfully.

• If Bootrec cannot find any missing Windows installations, you must remove the BCD store, and then you must re-create it. To do this, type the following commands in the order shown below: (Remember to press ENTER after each command)

bcdedit /export C:\BCD_Backup

ren c:\boot\bcd bcd.old

bootrec /rebuildbcd

- Restart the computer.

This should fix the problem.


Jan 15, 2005
Bravo, that's a great post.

I recently experienced the same issue and what saint and saran posted was the fix. Also, Zoron has some good advice. If the recovery works, you should immediately backup all of your important data. Bad sectors could be what caused the problem.