How can I rebuild the Windows boot files?

Question

After a virus, the boot files on a Windows 7 computer are gone, and I get this message when booting...

File: \Boot\BCD
Status: 0xc0000000f
Info: An error occurred while attempting to read the boot configuration data.

So I booted from my Windows 7 USB thumb drive and opened the command prompt. I mounted the drive with the OS install to the L: using diskpart, and then I changed to the L: drive then typed the following

L:\>bootrec /fixmbr
Command completed succesfully
L:\>bootrec /fixboot
Command completed succesfully
L:\>bootrec /rebuildbcd

I say I want to add the Windows install on L: so I type Y hit Enter and I get The requested system device cannot be found.

So how do I rebuild the Windows boot files; why can't the system device be found?

Below is a log of the commands I run as well as the windows usb install drives' attempt to repair it

---

When I click repair computer Windows scans for Windows Installs and then pops up this dialog

[[System Recovery Options]] <-- Title

Text is.... (no '-' though) -------------- Windows found problems with your computer's startup options. Do yo want to apply reparis and restart your computer?

View deatails

Then the buttons

[Repair and restart] [No]

When I click View details I get another dialog

[[Systen Recovery Options]]

Repair details: (then a scroll box with the deatils) The following startup option will be repaired: Name: {bootmgr} Identifier: {9DEA862C-5CDD-4E70-ACC1-F32B344D4795}

The following startup options will be added: Name: Windows 7 Home Premium (recovered) Path: Windows Windows Device: Partition=D: (595364 MB)

Name: Windows Recovery Environment (recovered) Path: Recovery\WindowsRE\Winre.wim Windows Device: Partition=C: (15000 MB)

A copy of the current boot configuration data will be saved as: C:\Boot\BCD.Backup.0002

[Close]

So I click Repair and restart and get

A error dialog that says [[System REcovery Options]]

X Failed to save startup options

[Ok]

So I click Ok

and get the normal windows that allows you to retore from an image or try and use recovery tools

Selected either options and clicking next gives me a dialog to Choose a recovery tool and buttons at the buttom to shutdwon or restart

So I open cmd and type the following

Microsoft Windows [Version 6.1.7600]

X:\Sources>diskpart

Microsoft DiskPart version 6.1.7600 Copyright (C) 1999-2008 Microsoft Corporation. On computer: MININT-8COAH39

DISKPART> list volume

Volume ### Ltr Label Fs Type Size Status
Info ---------- --- ----------- ----- ---------- ------- --------- -------- Volume 0 E DVD-ROM 0 B No Media Volume 1 C Recovery NTFS Partition 14 GB Healthy Volume 2 D OS NTFS Partition 581 GB Healthy Volume 3 F Removable 0 B No Media Volume 4 DELLUTILITY FAT Partition 100 MB Healthy Hidden

DISKPART> select volume 2

Volume 2 is the selected volume.

DISKPART> assign letter = l

DiskPart successfully assigned the drive letter or mount point.

DISKPART> exit

Leaving DiskPart...

X:\Sources>L:

L:>bootrec /fixmbr The operation completed successfully.

L:>bootrec /fixboot The operation completed successfully.

L:>bootrec /rebuildbcd Scanning all disks for Windows installations.

Please wait, since this may take a while...

Successfully scanned Windows installations. Total identified Windows installations: 1 [1] L:\Windows Add installation to boot list? Yes(Y)/No(N)/All(A):Y The requested system device cannot be found.

L:>bcedit 'bcedit' is not recognized as an internal or external command, operable program or batch file.

L:>

Answer 1

Try these general steps:

• Make another install of windows on the same disk on the same computer in a different partition. (Shrink your Windows partition and make a 30GB one, then install 7 in that.)
• Copy all of your boot files from the new install to the broken one using a Linux LiveCD (I would recommend Ubuntu as it comes with GParted, software which will allow you to do the aforementioned partitioning changes)
• Select your old 7 install from the boot menu and see if it works. If it does, delete the new partition and run startup repair.
• If it doesn't doesn't, consider using a Linux LiveCD (I prefer Ubuntu, a very user-friendly distro) to copy your data over to a new install of Windows, either disk-to-external-media-and-back-to-disk or just into a new Windows partition.

Answer 2

I have had the same problem... after two days of various trials, I tried:

bcdboot c:\windows

But it did not work for me so I tried:

bcdboot c:\windows /s c:

And all boot files were copied and the system is back online.

Answer 3

Assuming that c: is your system drive, and Windows is installed to the \Windows subdirectory, try running:

bcdboot c:\windows

Answer 4

I found a solution without a Live CD and a new Windows install.

I had exactly the same problem, but not from a virus but an SSD upgrade: I cloned my running Windows (both 100MB hidden partition and C:) to the new SSD via Reflect based on this tutorial then replaced the hardware.

My Windows was a traditional install Windows=C:, 100MB boot=hidden, but I think you can just fix any Windows installed to any drive letter. I was using the Windows 7 DVD to get to recovery mode.

The issue

So how do I rebuild the Windows boot files; why can't the system device be found?

The problem is that RebuildBCD requires the boot volume (the 100MB one) to have an assigned drive letter.

Recovery process

The Laptop couldn't boot, so I went into recovery mode where I was offered

[Repair and restart] [No]

where you have to say "No", because the drive letters are messed up and Windows won't start.

After "No" I started the command line, where the following happened:

X:\sources> diskpart
DISKPART> list volume

Table was showing 100MB system partition as C: and Windows as D: partition, the problem is that my original Windows was installed to C:, but now it's D:.

So I noted the Volume ### of the 100MB partition, say 1 and the Windows partition, say 2

DISKPART> select volume 1
DISKPART> active
DISKPART> assign letter=A
DISKPART> select volume 2
DISKPART> assign letter=C
DISKPART> exit
X:\sources> bootrec /rebuildbcd

Now bootrec found my missing Windows and fixed BCD. After a reset Windows just started up happily as nothing had happened.