The update to nvidia drivers crashed my windows 7 installation so i'm working to repair the damage

What I can do: I can boot Windows install from the USB drive, and I can boot the Hiren's Boot CD . Although automated windows repair fails, i can get to command prompt when i boot windows install from usb drive, and i can see my drive and all my data.

I can't start windows i get this message

Windows failed to start. A recent hardware or software change might be the cause. To fix the problem:
1. Insert Windows CD and run a repair your computer option.
File: /Boot/BCD
Status: 0xc000000f
Info: an error occurred while attempting to read the boot configuration data.

Something seems to be wrong with my bootbcd so i'm trying to recreate it from scratch I've tried all the methods detailed here (including Windows repair which fails), and I'm left with the last one (near the bottom of that page). When i type the following command in the tutorial

bcdedit.exe /import c:\boot\bcd.temp fails with the following error.

The store import operation has failed.
The requested system device cannot be found.

Many google results say that i must use diskpart to set my partition active, however it's already set as active.

It will come out when i try

bcdedit /enum

It fails with similar message.

The boot configuration data store could not be opened.
The requested system device cannot be found.

Does anyone know what does that error message mean, and what is the requested system device?

I'd like to avoid having to reinstall windows since all the files on the disk seem to be fine

Best Answer

Not directly related to your issue as you resolved it, but rather to your original description (particularly "The requested system device cannot be found." on BCD operations despite all attempts to recreate/rebuild).

This error can happen if you are booting from a USB stick, and your BIOS supports a given usb slot, but the windows PE/repair environment does not!

I spent two days pulling my hair out, wrestling with this issue (the BCD store was ALWAYS unavailable with this "The requested system device cannot be found." error, no matter what I did), only to find that the problem was simply the USB slot I was plugging my bootable USB stick in. By plugging it into a different (usb 2.0 instead of usb 3.0) slot, the standard repair actions worked fine.

To make things worse i later discovered that it was by plugging in the wrong slot and allowing the rescue environment to attempt auto-repair that i messed things in the first place

Update: another user (improvedcomputers) contacted me to confirm that this also happened to them; as all their usb slots were unrecognized by windows 7 pe they ended up having to pull the drive and perform the repair on another computer.

Update i had a hard time even reinstalling windows on my laptop From this post i learned that windows 7 pe does not recognize usb drives Although the boot image was based on a usb drive it did not start the installation process for some reason After whole day of efforts finally i tried it with dvd and it worked. I am using Lenovo W520