An unexpected I/O error has occured.File:\Boot\BCD

Hi  Agnes15,

Thank you for visiting Microsoft Answers.

It seems that the Boot Configuration Data (BCD) is corrupted.

Microsoft has completely reengineered the boot environment for Microsoft Windows Vista to address the increasing complexity and diversity of modern hardware and firmware. One aspect of this reengineering is a new firmware-independent data store that contains configuration data that influences the boot process. This paper provides an overview of this configuration data - called boot configuration data (BCD) - and describes how to use the related tools to manage boot options.

Step 1

Perform chkdsk which will repair the bad sectors of the hard drive.

To do this, follow these steps:

1.       Click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator.

2.       Type chkdsk/ f, chkdsk/r, chkdsk/i, chkdsk/c in the commands listed below  i.e. (/f, /r , /i, /c).

Step 2

Try to load BIOS to default and check if you have similar issue.

Step 3

I would suggest you to rebuilt BCD. To do this, follow these steps:

To run the Bootrec.exe tool, you must start Windows RE. To do this, follow these steps:

1. Put the Windows Vista or Windows 7 installation disc in the disc drive, and then start the computer.
2. Press a key when you are prompted.
3. Select a language, a time, a currency, a keyboard or an input method, and then click Next.
4. Click Repair your computer.
5. Click the operating system that you want to repair, and then click Next.
6. In the System Recovery Options dialog box, click Command Prompt.
7. Type Bootrec.exe, and then press ENTER.

8.       Type bootrec /RebuildBcd, and press Enter**.**

For more information refer the link given below:

How to use the Bootrec.exe tool in the Windows Recovery Environment to troubleshoot and repair startup issues in Windows

http://support.microsoft.com/kb/927392

Hope the information helps. Please post back and let us know.

Regards

Debleena S

Microsoft Answers Support Engineer.

I have exactly the same problem.  I'm not sure how I can follow the steps Debleena 5 outlines, when I am unable to see anything but a blank screen.  Even the recovery disk isn't working.  Any suggestions?

I have the same issue but the OS doesn't even appear. My option is to Load Drivers for my hard disks but where do I find them? There are 3 disks with Windows Recovery... I'd think they'd be on the first... I am directed to the System32 file which contains many, many files.

Thanks, Jared

Ok I am having the same problem BUt with Windows 7.  It is a brand new laptop.  I haven't even gotten to use it yet :/.  I start it up, answer the windows questions and then I get the mandatory hard drive partition screen.  I set the first partition to around 60 GB which is more then the recommended (tooling around forums that was what seemed a very safe number).  The computer goes to restart and then hits this error.  After hitting enter when this error appears to clear it, it once again shows the partition screen.  This cycle has happened 6 times in a row.  I have never used Windows 7 before and I am very confused.  Any help is appreciated.

After I put in bootrec/rebuildbcd I get a screen saying "Successfully scanned windows installations. Total identified windows installations: 1 [1] c:\windowns Add installation to boot list? Yes<y>/No<n>/All<a>: 

Which am I suppose to hit?