This article is specific to Windows 7 but similar errors occur on all versions of windows.
NOTE: You will need your Windows 7 DVD or a USB with the recovery console installed.
IF USING A USB STICK MAKE SURE IT IS PLUGGED INTO A USB 2 SLOT, USB 3 IS NOT SUPPORTED; It will error with ‘failure when attempting to copy boot file’.
After rebooting your computer you receive the following error:
Windows Boot Manager
Windows failed to start. A recent hardware or software change might be the cause. To fix the problem:
1.insert windos cd and run a repair your computer option.
Info: an error occurred while attempting to read the boot configuration data.
You may receive a similar error which lists the error code as 0xc0000034 or missing file: windows\system32\winload.exe instead.
You may also receive further errors after trying to repair the bcd store using bootrec and bcdedit as follows.
The requested system device cannot be found.
The “Windows Boot Configuration Data File is Missing Required Information
The “Windows Boot Configuration Data File is Missing
An error occurred while attempting to read the boot configuration data
Cause and Fix
The most likely cause of this error is that you tried to dual boot two operating systems and then later decided to remove one. This inadvertently may have deleted the bcd boot store. The trick here is to run the above commands in the right order and set your boot partition to active. Let’s get started.
Make sure your boot partition is set to Active
Boot from your DVD and choose the repair option. From the recovery console type “diskpart” and press enter and then type “list disk” to get a list of physical disks installed.
In the example here I only have one disk in my machine, if you have more than one identify the disk which has the Windows boot partition on it and then select it. Select it by typing “select disk 0” (in my case). Now type “list partition”. The Windows 7 boot partition is a 200 MB primary partition. As you can see here it was on disk 0. Select it by typing “select partition 2” or whichever number matches your 200MB partition.
Now type “detail partition” and look where it says “Active”. If it says yes then move onto the next section otherwise type “Active” and press enter, Windows should report the partition is now marked as active. Now reboot and boot into the recovery console again.
Repair the MBR and boot sectors
From the recovery console run these commands in this order:
- bootrec /fixmbr
- bootrec /fixboot
Now reboot the machine again into the recovery console and type “bcdboot path to your windows folder“. Your windows folder will normally be c:\windows but in the recovery console it may show up as D:\windows so make sure you get the path right. In my case it was “bcdboot d:\windows”. This will will build a new bcd boot store and copy over all boot files needed to boot. Now reboot your machine one last time and it should work. If it doesn’t run the two bootrec commands again.
If you have any additional operating systems you want to add use the bootrec /scanos command.
If you still have issues you may have a system with a GPT disk. In this case you will have an EFI sytem partition that must always be active. See the following if you get Failure when attempting to copy boot files or suspect you have an EFI system.