For example, you receive one of the following error messages.
Recovery
Your PC needs to be repaired
The Boot Configuration Data file is missing some required information.
File: \BCD
Error code:
0xc0000034
Recovery
Your PC/Device needs to be repaired
A required device isn't connected or can't be accessed.
Error code:
0xc0000225
BCDBOOT - Bcd boot file creation and repair tool.
BCDboot <source>
- <source> Specifies the location of the Windows directory to use as the source for copying boot files.
UEFI Boot Mode: BCDboot copies the boot files from the Windows partition to the EFI System partition and creates the BCD store in the same partition.
Legacy BIOS Boot Mode: BCDboot copies the boot files from the Windows partition to the active partition on the primary hard drive and creates the BCD store in the same partition.
https://msdn.microsoft.com/en-us/library/windows/hardware/dn898490(v=vs.85).aspx
Repair the system partition. If the system partition has been corrupted, you can use BCDBoot to recreate the system partition files by using new copies of these files from the Windows partition.
Set up or repair the boot menu on a dual-boot PC. If you've installed more than one copy of Windows on a PC, you can use BCDBoot to add or repair the boot menu.
How to use the BCDboot command in Windows 7/8/10.
Open the command prompt as administrator.
-or-
Boot the computer using the Windows 7/8/10 installation media.
On the first screen, press
SHIFT+F10 to bring up the command prompt.
-or-
Boot the computer using the Windows 8/10 Recovery USB flash drive.
Select
Troubleshoot >
Advanced options >
Command Prompt.
Run the following commands at the command prompt.
diskpart
list volume Note: Note the volume letter where the Windows OS is installed.
exit
bcdboot X:\windows Note: Replace "X" with the volume letter of the Windows OS partition.
For example,
bcdboot c:\windows or
bcdboot d:\windows (see screenshots below).
If the drive letter is incorrect, you will receive the following error message: "
Failure when attempting to copy boot files".
Note: But if you get that error message even if the drive letter is correct, then take a look at this post if the hard drive has an
MBR partition table. ->
link
Tip
The following is an example how do you fix a dual-boot system (see screenshot below).
Now you should see the dual-boot screen (see screenshot below).
Tip
If you have a
Windows 7 style dual-boot screen (see screenshot above) and if you want a
Windows 8/10 style dual-boot screen.
When you are in
Windows 8/10, open the Command Prompt (Admin) and type:
bcdboot %windir%
Other instructions.
How to create a bootable
Windows 10 USB flash drive or DVD. ->
link
How to download and clean install
Windows 8.1 if you have an OEM computer with UEFI firmware (BIOS) embedded
Windows 8/8.1 product key. ->
link
Here is info about
UEFI Boot Mode (installing using the
GPT partition style) and
Legacy BIOS Boot Mode (installing using the
MBR partition style):
link