Checking Windows for integrity. Using the standard SFC utility. Running SFC using the recovery environment

Hello friends! This article is a logical continuation of the recently launched epic about the fight against. And now the author will share with you one more effective method eliminate such troubles.

Therefore, the topic of the story will sound like this: the SFC scannow command in Windows 7 and 10. We will also consider the question of why sometimes it cannot restore system files. That is, simply put, it refuses to work.

So, what kind of command is this and what is it for? So, SFC scannow is system utility, which serves for automatic check and recovery important files operating system.

It is quite easy to use, but sometimes various nuances may arise. So let's get down to business to understand everything. All further actions will be shown on Windows example 10, although in Win 7 everything is done almost the same way.

Then enter the command itself:

The system scan process will begin, which may take quite some time. long time. So now all we can do is wait and hope that this command can fix everything.

After finishing the work, a report will appear, which will tell you about real situation business You will also have the opportunity to familiarize yourself with the log file and understand in detail the important details:

But as you can see in the screenshot above, in our case everything did not go very smoothly. Damaged files were detected, but Windows 10 was unable to restore them.

This happens because the SFC scannow parameter is unable to restore those system files that are used in this moment time by the operating system itself. In general, a real paradox emerges.

But nevertheless, there is a way out of this situation. You need to try to perform the above actions in the environment Windows recovery. How to enter it on the tenth version of the system is described in great detail in

Well, on the seven you will have to use a previously prepared boot disk and set it as priority on the computer. Alas, there is no other way.

Well, we continue the process of treatment and file recovery using Win 10 as an example. And now you will need to enter a small series of commands. The first one will be like this:

With the next function we will print common list installed on computer hard disks. Each of them has already been assigned personal number, which we will need in the next step:

Now select the disk number zero discovered above, since it is the only one in the system:

At this stage, all that remains is to sort out the hard drive in order to understand which one is the system one, that is, with Windows installed:

After necessary information received, you can, so to speak, and move on from here. To do this, enter next command:

And now, finally, the hour of truth has come. Now we will check the system files again and, in case of problems, try to restore them. So, let's start the process:

In this expression, the letter "C" indicates logical hard section disk on which the operating system is installed. Also, when entering, it is very important to ensure that the input is correct, in particular, to put problems where necessary.

Now we can only hope that after the scanning process is completed, the message “Protection Windows resources did not detect any integrity violations.”

What else can you tell about the SFC scannow command? For example, this parameter will be able to display a log with the results of work on the desktop in the recovery environment:

And the following method will allow you to check and restore a specific file. For example, in work Windows given the parameter will look like this:

Where "kernel32.dll" represents the name the desired file. And the entire expression is the path to the directory where it is located. The exact same command in the Windows 7 and 10 recovery environment will be slightly different:

Well, friends, now you know why sometimes the SFC scannow command in Windows 7 and 10 cannot restore system files. But in conclusion, it’s worth saying that there is another similar utility, which we also .

If you suddenly have any questions, feel free to ask them in the comments to the article. Now you can relax a little and watch a very interesting video. Guys, you definitely need to watch this.

No user is immune from errors in the Windows 10 operating system. They can arise due to its purposeful or accidental interference in the operation of the OS, as well as due to the fault third party applications. If the operating system begins to complain about missing files, registry errors, or the inability to read items from Windows folders, you will need to check the integrity of its components.

The Windows 10 operating system provides 2 methods for analyzing file integrity - through the SFC.exe and DISM.exe tools. The commands do not replace each other, but complement each other, checking various system libraries for file integrity. That is why it is recommended to do not one of them, but both. Tools will allow you to check the integrity Windows files 10 and replace damaged or altered items with original ones.

Important: If the computer user previously made reasonable changes to the system files of the operating system, they will be canceled. Windows Tools will replace the changed elements with the original ones, even if the problem in the operation of the computer or application is not caused by their actions.

How to check file integrity in Windows 10 using SFC

It is recommended to start checking the integrity of operating system files with the SFC command. It allows you to find errors in key files and fix them. You can check using SFC as in familiar interface Windows 10 through the command line and through the recovery environment, both of these methods are described below.

Via the command line in the Windows interface

It is better to start checking using SFC through the standard Windows interface using the command line. Most often this is enough. To check the integrity of the files you need to do the following:

If there are no problems with the Windows system files, after checking the user will see a message that “Windows Resource Protection did not detect an integrity violation.” In such a situation, you can proceed to checking files using DISM.

However, in some situations, files that are responsible for displaying may not work correctly. GUI Windows and the system will not be able to fix them, since they are active. In such cases it is necessary to carry out SFC check through a recovery environment that does not require loading a graphical interface and is capable of working with these files, as well as changing them if necessary.

Please note if you suspect that the system malfunction is due to specific file, may not be performed full check SFC. Just enter the command sfc /scanfile=”address to file”, and it will be replaced instantly with the original version if changes were previously made to it or it works with an error.

Via recovery environment

To check the integrity of files using the SFC command through the recovery environment, you will need to perform the following steps:

Click on the Start button in the lower left corner and go to Settings:

After executing the second command, a list of available volumes will be displayed. Here you need to pay attention to the disk that is reserved by the system and to the system partition with the operating system. Next, you will need to manipulate them.

Continue typing the commands:

Exit sfc /scannow /offbootdir=C:\ /offwindir=E:\Windows

The last command requires you to specify the drives that were noted above. That is, in the above command example, drive C is the partition with the bootloader, and drive E is the place where the operating system is installed Windows system 10.

Attention: There is a good chance that your drive letters will be different from those given in the example, so the command will vary.

1. After entering the last of the four commands, an integrity scan of the operating system files will begin.

The advantage of working through the recovery environment is the ability of the SFC tool to replace the files that are needed to boot the graphic Windows interface. Check in in this case will take a little longer than when working through the command line in the operating system interface. At the same time, graphically the user command line in the recovery environment will not notify you about the speed of the process. You can determine that the computer is working properly and the file integrity check has not frozen by the blinking underscore icon.

At the end of the scan, the user will see information that no integrity violations were detected or were successfully resolved. After this, you can move on to the second verification method - using the DISM tool.

How to check file integrity in Windows 10 using DISM

As noted above, after checking using SFC, it is recommended to start analyzing the system with the DISM tool. During the scan, it will examine other directories (and will once again “go through” the files that were scanned by SFC).

Scanning with the DISM tool is slightly different from analyzing the system using SFC. The user has the opportunity to select one of three commands to check the system. Each of them has different level impact.

Dism /Online /Cleanup-Image /CheckHealth

When executing this command, the system checks what has been done diagnostic utilities records on detection of changed or problematic files in the system. The command is executed quickly, but there is no verification, and all data is based on previously recorded information.

Dism /Online /Cleanup-Image /ScanHealth

This team is aimed at analyzing all system components to identify errors and damaged elements in them. In this case, only a check is carried out, and the user is notified of the presence or absence of problematic files. This check can take from several minutes to several hours, depending on the speed work hard disk, its load and the degree of interference with operating system files.

Dism /Online /Cleanup-Image /RestoreHealth

This command, unlike the previous one, not only checks the files, but also immediately replaces them with intact ones. It will also take from several minutes to several hours to complete.

Important: Please note that the last two commands that run the Windows 10 file integrity check may freeze at a certain percentage during execution (usually around 20). Under no circumstances should you reboot the system at this moment, because this situation is typical and interest will continue to accrue over time.

Each of us copies files from time to time. Moving or copying documents to external devices, such as flash drives. Backup multiple directories from one drive to another. Using programs to synchronize files from multiple sources. In most cases, copying files like this will be normal and will not cause any problems. However, at least once, everyone has encountered the problem of corrupted files, when a newly copied file becomes unusable or loses some data. The most unpleasant thing about such an error is that you can find out about it after a long time and precisely at the moment when you need the file.

Many backup and directory synchronization programs include additional functions checking the integrity of the created copies. However, from time to time, file corruption can occur due to glitches or errors in the programs themselves. For example, when you simply copy files using Windows Explorer, then the operating system checks the integrity of files based on CRC (a special number, also called a checksum, calculated based on file data) and this check, in most cases, helps to avoid errors. However, failures in system components or defects hard drive may cause your copy of the file to eventually become corrupted. In addition, in the case of transmission over a network, there is a possibility that some of the bits were transmitted incorrectly, which is why the resulting copy, despite checks, will be damaged.

To avoid similar problems, They were designed special programs file integrity checkers, which perform additional rigorous tests on files to confirm data integrity. Most of these tools use various methods checksum calculations and hash functions to check each file for discrepancies with the original. So if a copy of the file has been changed even in the slightest way, the difference in the final checksums (hash function values) will quickly become apparent.

This technique is widely used on the Internet to allow users to quickly verify that downloaded files are a complete copy of the original ones. If you've ever noticed, sometimes files on pages are accompanied by small lines to verify the file. More often, we're talking about about strings with a check number calculated based on the MD5 or SHA1 hash function. The same technique is used to check originals and copies of files for integrity.

ExactFile is one of free utilities, which makes it easy to check hash functions for large sets files. You can download the program from the developer's page using this link. Using ExactFile is very easy. To check directories, you need to go to the "Create TestFile Applet" tab, then select the desired directory and algorithm for calculating the checksum value (MD5 by default). Then press the “Go” button. The process of calculating checksums will begin. At the end of the process, two files will be created in the directory being checked - “TestFiles.exe” (a file to start checking the sums of the current directory) and “checksums.exf” (a file within which all checksums files in this directory). Now, to check the integrity, you just need to run TestFile.exe. As part of the scan, not only changed files will be displayed, but also missing ones. So if you need to check a copy of the directory, then just copy these files to the directory with the copy and run "TestFile.exe".

One of possible scenarios using this program is sharing with applications for Reserve copy. The algorithm in this case will be quite simple. First you run ExactFile, which creates a TestFile applet to test the files and their data inside the directory. Then you back up your files. And at the end, run TestFile.exe in the backup copy. There is a console line version of ExactFile that can be used in batch files together with other programs, such as with the same backup.

One limitation of using ExactFile with backup applications is the backup method used. So for example, if the backup is compressed to archive file, then you will not be able to run testing of the copy, since for this you need to unpack the archive. Therefore, ExactFile can only be used when creating mirror backups.

Note: In the case of a full backup, you can use the trick of creating a virtual disk based on the archive using the WinMount program. And already on virtual disk run file scan.

ExactFile is especially useful for verifying the integrity of file backups when creating CDs and DVD discs. ExactFile will also be very useful when using synchronization programs or checking the integrity of copied files over the network.

Overall, ExactFile is a great little utility with a lot of potential.

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