Bcdboot exe crashes when copying files. What is a bootloader? Automatic Windows Boot Loader Repair

In this article, we will figure out how to restore the Windows 10 or Windows 8.1 bootloader on a computer running in . Damage to the Windows 8 bootloader can be caused by installing a second OS (Dual Boot configurations), incorrect actions of a “specialist” when restoring the system after a failure, deleting “extra” data on hidden partitions, a ransomware virus, and a number of other reasons.

Boot error The boot configuration data for your PC is missing: EFI\Microsoft\Boot\BCD

Damage to the Windows 10/8.1 bootloader installed in UEFI mode may be indicated by the inability to boot the system and the appearance of a new blue “screen of death” with the error:

The boot configuration data for your PC is missing or contains errors.
File:\EFI\Microsoft\Boot\BCD
Error code: 0xc000000f

In the Russian version of Windows, the error may look like this:

Your computer needs repair
Boot configuration data for your PC is missing or incorrect
File:\EFI\Microsoft\Boot\BCD
Error code: 0xc000000f

All this may indicate damage or even complete deletion of the Windows 8 bootloader configuration - Boot Configuration Data (BCD). Restoring the BCD boot loader using one of the previously discussed methods ( , ) will not work: when you try to execute the bcdedit command, the system displays an error:

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

The fact is that the BCD BCD boot loader configuration in Windows 10/8 installed in UEFI mode is stored on a separate hiddensection EFI(100 MB in size with the FAT32 file system), which the bcdedit utility does not see, and accordingly cannot manage the bootloader configuration on it.

Automatic Windows Boot Loader Repair

The automatic bootloader recovery procedure built into , as a rule, is powerless in such cases. But it's still worth a try:

Manually repairing the Windows boot loader using a boot disk

Let's move on to the procedure for restoring the Windows bootloader on a system with EFI.

So, to restore the boot loader (BCD) configuration, you need to boot from the original Windows 8 installation DVD (or recovery disc or) and open a command prompt window: by selecting System Restore -> Diagnostics -> Command Line(System Restore -> Troubleshoot->Command Prompt), or by pressing the key combination Shift+F10).

Let's launch diskpart:

Let's display a list of disks in the system:

Let's select the disk on which your Windows is installed (if there is only one hard disk in the system, its index should be 0):

Let's display a list of partitions in the system:

In our example, you can see that the EFI partition (it can be determined by its size of 100 MB and the FAT32 file system) has an index of volume 1, and the boot partition with the installed Windows system (this can be either Windows 10 or Windows 8.1/8) has a volume 3 .

Let's assign an arbitrary drive letter to the hidden EFI partition:

assign letter M:

A line should appear indicating that the drive letter was successfully assigned to the EFI partition:

DiskPart successfully assigned the drive letter or mount point.

Finishing work with diskpart:

Let's go to the directory with the bootloader on the hidden partition

cd /d m:\efi\microsoft\boot\

In this case, m: is the drive letter assigned to the UEFI partition just above. If the \EFI\Microsoft\Boot\ directory is missing (The system cannot find the path specified error), try the following commands:

cd /d M:\ESD\Windows\EFI\Microsoft\Boot\

Let's recreate the boot sector on the boot partition:

bootrec/fixboot

Let's delete the current BCD configuration file by renaming it (saving the old configuration as a backup):

Using the utility bcdboot.exe Let's recreate the BCD storage by copying the boot environment files from the system directory:
bcdboot C:\Windows /l en-us /s M: /f ALL
Where, C:\Windows– path to the directory with Windows 8 installed.
/f ALL– means that it is necessary to copy boot environment files, including files for computers with UEFI or BIOS (theoretical ability to boot on EFI and BIOS systems)
/l en-us— system locale type. The default is en-us - English (United States).

Advice. If you use a localized Russian version of Windows 10 / Windows 8, the command will be different:
bcdboot C:\Windows /L ru-ru /S M: /F ALL

Possible mistakes:

• BFSVC Error: Can't open the BCD template store. status – – check the correctness of the entered command and whether you are using localized Windows, in this case you need to correctly specify the system language code (local language code)
• BFSVC Error: Error copying boot files Last Error = 0x570 – try checking the disk using CHKDSK M: /F

Run the commands:

bootrec /scanos
bootrec /rebuildbcd

All that remains is to restart the computer, after which the Windows Boot Manager item should appear in the selection of boot devices, in which you can select to boot the desired OS. BCD boot loader configuration successfully restored!

It happens that when you turn on the computer after an improper shutdown, a power outage, or installing a second operating system, a message appears on the screen stating that the boot disk or boot loader cannot be detected. In order to start the computer in this case, you need to restore the Windows 10 bootloader. But you should immediately find out what it is, and also consider the reasons for the appearance of such errors.

What is a bootloader?

The OS operating system loader is a program that allows the OS to start after successful completion of the computer's self-test when turned on. This very testing of PC hardware components is carried out by a set of BIOS microprograms, after which it transfers control of the system to the bootloader, which already launches the operating system.

This scheme is relevant not only for computers and laptops; it is used in many devices: simple logic controllers, smartphones and other mobile devices.

The bootloader performs several functions besides starting the OS:

• prepares the hardware to load the operating system kernel;
• launches the OS kernel stored on HDD, SDD or transmitted over the network;
• transfers control of the device to the operating system kernel.

Causes of the problem

The error message occurs after the initial boot phase of the computer has completed, and the boot loader, which needs to transfer control of starting the OS, is not found in the specified location (the first sector of the boot disk). There are several reasons for errors regarding the absence of a boot record:

• presence of bad sectors on the disk;
• absence of a bootloader file, which in the top ten is called bootmgr;
• careless handling of programs for creating multiboot configurations (EasyBCD);
• installing an older operating system on top of a new one and generally installing a second OS.

Solution

Restoring the Windows 10 bootloader is carried out using several methods using the command line. If the user is new or unfamiliar with this system tool, there is no need to worry. There is absolutely nothing complicated here, and even a beginner can cope with resuscitating the bootloader by strictly following the given instructions.

Before you begin recovery, you need to perform a few simple operations:

• disconnect all external storage media (flash drive, camera, e-reader, smartphone) from the computer, and if
• capabilities, and all other USB devices except the mouse and keyboard;
• go to the BIOS section, most often called “Boot” or “Boot priority”, and select as the 1st boot device
• hard drive where Windows 10 is located.

If after a reboot the problem does not disappear, we move on to more drastic solutions.

Method No. 1

To restore the boot loader in Windows 10 (and any other Windows, starting from Windows 7), you will need a distribution kit with operating system installation files. Most likely, it will be a bootable USB flash drive created from an ISO image. A Windows 10 recovery disc will also work.

1. Connect a bootable USB flash drive, restart the computer and boot from this drive using the “Boot menu”.

It is usually called up using the F9, F11 or F12 key. In any case, information about this is displayed at the time of self-testing of PC hardware components.

2. Go to the “tens” recovery environment by clicking on the link of the same name on the screen with the “Install” button.

3. Go to click on the icon with the inscription: “Troubleshooting” and call up additional parameters.

4. Launch the command line.

By the way, by selecting the “Startup Repair” option, the steps below can be automated, but the method does not always work.

5. Enter a sequence of system commands, executing them by pressing the “Enter” key:

• diskpart - to launch a utility that allows you to work with disk partitions;
• list volume - visualizes data about the partitions of your hard drive (remember the letter label of the volume on which Windows is located);
• exit - exit from the Diskpart program.

6. Execute the command “bcdboot x:\windows”, where x is the letter of the partition with OS files.

7. After a message appears about the successful creation of the download files, restart the computer.

Method number 2

If restoring the Windows 10 bootloader using the proposed method failed, repeat all the steps given in the first section, up to the 4th step.

If you are using a PC with a new UEFI interface and a GPT partition scheme, look for a hidden volume formatted in FAT32, the size of which ranges from ~300-500 MB. When using an old motherboard with a BIOS, we are looking for a ~450 MB volume with the same file system.

2. Remember the section number, for example, “Volume 3”, and its letter label.

3. Execute the chain of commands below:

select volume X, where X is the drive letter;
format fs=fat32 or format fs=ntfs, depending on the file system;
assign letter Y - assign a letter label to the disk;
exit - unload diskpart from RAM;
bcdboot C:\Windows /s Y: /f all, (C:\ - system partition):
diskpart
list volume
select volume X;
remove letter=Y - disables display of the service disk in Windows;

4. Close the command line and reboot.

Method No. 3

Restoring the bootloader using the above methods is impossible without having bootable media with Windows 10 installation files, so let’s consider the simplest (but not the most effective) option for restoring the “ten” bootloader. To do this, we launch “Special download options,” which is not always possible. In additional parameters, open the command line, execute the command “bootrec.exe /fixboot” and reboot the computer. This concludes the methods for restoring the Windows 10 bootloader.

It is reliably known that Linux Ubuntu does not want to become close to the top ten. The most unpleasant thing is that the reason is unclear. Before this, there was a failure when copying download files at a certain stage of the installation, and when a dozen settled on the hard drive, Linux was completely offended. Now the Linux boot package warns in advance that it will not stand next to Billy Gates' brainchild. We decided to find out what’s going on here, and at the same time we’ll describe how to restore the Windows 10 OS bootloader.

If your PC does not want to boot, do not rush to restore the system. Practice shows that this occurs when someone forgot the SD card from the camera in the Card-Reader. There's just a black screen and that's it. The BIOS boot loader takes this media as a disk with the system and gives control to it. As if there was an installation flash drive. No system restore is required. Turn off the PC, remove the removable media, and restart.

Via bootable media

If you know for sure that the boot is coming from the desired Windows system media, but something goes wrong, obviously, you still have to tinker.

Damaged hard drive

Not long ago, a virus appeared, undetectable in the standard way, which erases the system area. It overwrites files over and over again until it completely erases everything. This leads to the formation of poorly readable sectors. The access period for which is from 1500 ms and above. As a result, the boot time of Windows 10 increases greatly and can reach half an hour. It's almost useless to fight. Such cases are described on forums. Attempts are made to move the system partition, but they lead nowhere.

The worst thing is when the same situation is observed when exiting hibernation. Because some were saved by this particular mode (the difference in loading speed is up to 10 times). Noteworthy is the fact that the “five rotating points” of the window can slow down or behave normally. In both cases it takes a long time to load. So, there is only one way out - to use the hard drive only for storing information.

Bootable media

Windows OS has a built-in boot file control tool. It’s logical to start bootloader recovery from here. The next section will show you how to enter the command line, but for now we assume that readers can do this themselves:

If the first method does not help, then the system partition (500 MB) is formatted, then the copying procedure is performed again (find details of working with Diskpart below). In this case, you need to explicitly specify the drive letter using the key. The screenshot shows an example from the official Microsoft website (technet.microsoft.com/ru-ru/library/dd744347(v=ws.10).aspx), writing all data to section S.

We don't really need the /l parameter to set the language, and we can throw that part out. The partition is formatted for reasons that the system could be damaged by a virus. After all the manipulations have been completed, the ten usually starts to load.

How to open the recovery tool

In the top ten, the developers devoted a lot of effort to creating a recovery environment. In this case, you will have to start from the media (although Microsoft TP writes that the same can be done using three consecutive emergency power outages). But in our case it is assumed that the hard drive is completely useless. Therefore, we are looking for a flash drive or DVD to start operations. To transfer control to the desired media at the very beginning (immediately after turning on the PC), patiently press F12. From the menu that appears, select the desired line.

Please note that USB drives often end up in the hard drive partition. Start loading and wait for the first meaningful window to appear. Here you will be asked to select a language, leave the default Russian. We are interested in the recovery tool.

How to label a volume

You have seen that it is very difficult to find the partition with the operating system through the command line in order to perform a boot restore. The process looks much easier when the volume has a label. Meanwhile, creating it takes a matter of seconds. To do this, go to Explorer and right-click on the desired section. In Properties there is the required field.

Fill it out and click apply. After this, the system disk can be found without problems from the Diskpart utility.

Working with Diskpart

The Diskpart utility is part of Windows, and in this case it is the only way to find out more about our hard drive.

The shrink command reduces the size, and create creates a new partition in this place. In our case, we should not delete the old one, allocated by the regular wizard, so as not to inadvertently create a new one in the same place.

How to create a new boot partition

We decided to reveal a little example of creating a new boot partition. The unnecessary logical disk was removed, after which the process started. See what it looks like.

All! You can get overloaded. In addition, we erased C as unnecessary. Ten managed to load a little faster. This disk is erased by a virus and cannot be used as a working disk. But it was the easiest way to demonstrate bootloader recovery in the Windows 10 operating system. Everything works. The system booted successfully.

In the article we restored the MBR bootloader using BOOTREC.EXE And BOOTSECT.EXE. And if the previous instructions did not help you or everything ended in error bootmgr is missing. Or you just started working with this particular error. You are welcome to our hut!

BCDBOOT- a tool that is used to create a system partition or restore the boot environment located on the system partition. The system partition is created by copying a small set of boot environment files from an installed Windows® image. Means BCDBOOT creates a boot configuration data store ( BCD) on the system partition with a new boot entry that allows you to boot the installed Windows image.

Perhaps I didn’t write it very clearly, hmm. To put it simply, this is a tool that restores system and boot files in a small hidden partition. Which is created at the very beginning of Windows installation. It contains the Windows RE environment, as well as download files.

In fact, not everything is so categorical; disk layouts are different and situations are different. It happens that this section is missing or damaged. And the bootmgr file itself is missing. Sometimes the boot record itself does not find this file due to damage to the file system of the partition on which the boot files are located. For some reason, this has become a common occurrence in Windows 10. So keep in mind... In such cases, a simple command always works well CHKDSK C: /f /r

With this command, you check all partitions associated with the operating system, or all partitions in turn. And it is likely that the system will start.

But if the download files were left on another hard drive, say if you temporarily connected an additional hard drive to copy files. And quite by accident, the temporary disk was identified as the first one in the system at the time of Windows installation. And when it was turned off, the system could not start correctly. Or you just got confused about the partition parameters and something went wrong. In all these cases it will help BCDBOOT. This is what we will now try to figure out.

BCDboot command line options.

BCDBOOT source ]

Parameter	Description
source	Specifies the location of the Windows directory used as the source when copying boot environment files.
/l	Optional. Sets the language. The default is English (US).
/s	Optional. Specifies the drive letter of the system partition. By default, the system partition specified by the firmware is used.
/v	Optional. Enables detailed logging mode.
/m	Optional. By default, only merges global objects. If an operating system boot loader GUID is specified, combines the boot loader object with the system template to create a boot entry.

The command line in this case might look like this:

bcdboot.exe c:\windows

Replace c:\windows to the path appropriate for your system.
This operation will repair the corrupted Windows boot environment, including the boot data configuration store files ( BCD), including the bootmgr file mentioned above. And the message “ Upload files created successfully" or " boot files successfully created» Depending on the localization of the Windows RE environment.

If after entering the command you get the error “ Failure to copy download files»

This means only one thing - there is not a single active partition on the hard drive! This rule applies to computers with UEFI turned off, that is, Windows is installed on an MBR disk. In order for the BCDboot utility to restore the bootloader, the presence of an active partition on the MBR hard drive is required.

To work with partitions, the system has a fairly effective tool - diskpart. This is a text-mode command interpreter for Windows Vista/7/8/8.1/10 operating systems. The tool allows you to manage objects (disks, partitions, or volumes) using scripts or commands entered from the command line.

So, let's try to make the system (which is “reserved by the system”, usually the download files are located there) partition active. To do this, in the command line of the Windows RE environment, enter the following commands one by one:

diskpart

lis vol(we display a list of hard drive partitions and see that “Volume 1” is a hidden System Reserved partition, volume 500 MB, Windows 10 download files should be located on it and this is what needs to be made active). We also see a partition with Windows 10 installed, its letter is WITH:, volume 60 GB.