If you are running Windows 10, Windows 8.1 or Windows 8, first run the inbox Deployment Image Servicing and Management (DISM) tool prior to running the System File Checker. (If you are running Windows 7 or Windows Vista, skip to Step 3.)
Important: When you run this command, DISM uses Windows Update to provide the files that are required to fix corruptions. However, if your Windows Update client is already broken, use a running Windows installation as the repair source, or use a Windows side-by-side folder from a network share or from a removable media, such as the Windows DVD, as the source of the files. To do this, run the following command instead:
Note: Replace the C:\RepairSource\Windows placeholder with the location of your repair source. For more information about using the DISM tool to repair Windows, reference Repair a Windows Image.
The sfc /scannow command will scan all protected system files, and replace corrupted files with a cached copy that is located in a compressed folder at %WinDir%\System32\dllcache.
The %WinDir% placeholder represents the Windows operating system folder. For example, C:\Windows.
Note Do not close this Command Prompt window until the verification is 100% complete. The scan results will be shown after this process is finished.
To repair the corrupted files manually, view details of the System File Checker process to find the corrupted file, and then manually replace the corrupted file with a known good copy of the file.
Swipe in from the right edge of the screen, and then tap Search. Or, if you are using a mouse, point to the lower-right corner of the screen, and then click Search. Type Command Prompt in the Search box, right-click Command Prompt, and then click Run as administrator. If you are prompted for an administrator password or for a confirmation, type the password, or click Allow.
To view the details that included in the CBS.Log file, you can copy the information to the Sfcdetails.txt file by using the Findstr command, and then view the details in the Sfcdetails.txt. To do this, follow these steps:
Note The Sfcdetails.txt file contains details from every time that the System File Checker tool has been run on the computer. The file includes information about files that were not repaired by the System File Checker tool. Verify the date and time entries to determine the problem files that were found the last time that you ran the System File Checker tool.
After you determine which system file was corrupted and could not be repaired through the detail information in the Sfcdetails.txt file, find where the corrupted file located, and then manually replace the corrupted file with a known good copy of the file. To do this, follow these steps:
Note You may be able to get a known good copy of the system file from another computer that is running the same version of Windows with your computer. You may perform a System File Checker process on that computer to make sure the system file that you intend to copy is a good copy.
Copy Source_File DestinationNote The Source_File placeholder represents the path and file name of the known good copy of the file on your computer, and the Destination placeholder represents the path and file name of the corrupted file. For example, type copy E:\temp\jscript.dll C:\windows\system32\jscript.dll.
System File Checker gives an administrator the ability to scan all protected files to verify their versions. If System File Checker discovers that a protected file has been overwritten, it retrieves the correct version of the file from the cache folder (%Systemroot%\System32\Dllcache) or the Windows installation source files, and then replaces the incorrect file. System File Checker also checks and repopulates the cache folder. You must be logged on as an administrator or as a member of the Administrators group to run System File Checker. If the cache folder becomes damaged or unusable, you can use the sfc /scannow, the sfc /scanonce, or the sfc /scanboot commands to repair its contents.
/Scanonce: Scans all protected system files one time when you restart your computer. This command may require access to the Windows installation source files when you restart the computer. The SfcScan DWORD value is set to 2 in the following registry key when you run this command:
/Scanboot: Scans all protected system files every time you start your computer. This command may require access to the Windows installation source files every time you start your computer. The SfcScan DWORD value is set to 1 in the following registry key when you run this command:
/Revert: Returns scan to the default setting (do not scan protected files when you start the computer). The default cache size is not reset when you run this command. This command is equivalent to the /Enable switch in Windows 2000.
/Cachesize=x: Sets the file cache size to x megabytes (MB). The default size of the cache is 50 MB. This command requires you to restart the computer, and then run the /purgecache command to adjust the size of the on-disk cache. This command sets the SfcQuota DWORD value to x in the following registry key:
To use System File Checker from the Command Prompt through Advanced Startup Options or System Recovery Options, see the Executing SFC /SCANNOW From Outside of Windows section below for some necessary changes in how you execute the command.
Sfc /scannow scans your system files while the chkdsk command is used to check a specified disk and repair or recover data on the drive if necessary. Chkdsk also marks any damaged or malfunctioning sectors on the hard drive or disk and recovers any information still intact.
I just ran a scan and it said beginning your verification phase and now it's a hundred percent complete. Then it said windows resource protection did not find any integrity violations. What does that exactly mean?
Will running this have caused any damage to my operating system or computer or hardware like the hard drive or motherboard in anyway? I ran it as an administrator and not in safe mode. Is it okay if I was googling things on a browser while it was running? What happens if it is not run as an administrator? I'm pretty sure I did but sometime when I try to do other things or log in as an administrator it says I'm not allowed. If for some reason it didn't run as an administrator will anything be corrupted?
1. Turn off the computer and wait five seconds.
2. Press the Power button to start the computer and repeatedly press the F10 key to enter the BIOS setup menu.
3. On the BIOS Setup screen, press F9 to select and load the BIOS Setup Default settings.
4. Press F10 to Save and Exit.
5. Use the arrow keys to select Yes, then press Enter when asked Exit Saving Changes?
6. Follow the prompts to restart your computer.
Also, I would suggest you enable Fast Start-Up on the system and check if it helps. To do this, follow the steps below.
1. Open Control Panel and go to Power Options.
2. Click/tap on the Choose what the power buttons do link on the left side.
3. Click/tap on the Change settings that are currently unavailable link at the top.
4. If prompted by UAC, then click/tap on Yes.
5. Ensure that Turn on Fast Startup is checked.
6. Restart the computer.
In Windows, search for Command Prompt. In the search results, right-click Command Prompt and select Run as administrator. Then click Yes.
In Command Prompt, type sfc /scannow. Make sure to include the space between sfc and the /.
Press Enter and wait while System File Checker scans for corrupted files.
When scanning is complete, the results are displayed on the screen.
If the file checker found and replaced any corrupted files, restart the computer and check the performance.
If the file checker did not find any corrupted files or found corrupted files but could not replace them, go to the next step.
If System File Checker finds corrupted files but cannot replace them, use the Deployment Image Servicing and Management (DISM) tool. DISM checks the corrupted files; then downloads and replaces the files using Windows Update.
In Windows, open a web browser.
NOTE:
You need to be connected to the Internet to use DISM.
In Windows, search for Command Prompt. In the search results, right-click Command Prompt and select Run as administrator. Then click Yes.
In Command Prompt, type dism.exe /Online /Cleanup-image /Restorehealth. Make sure to include the space before each / in the command line.
Press Enter and wait while DISM works. This might take several minutes.
If DISM finds corrupted files, it replaces them using Windows Update. If this occurs, after DISM is finished, restart your computer and see if the performance has improved.
Microsoft ships this utility with Windows 98, Windows 2000 and all subsequent versions of the Windows NT family of operating systems. In Windows Vista, Windows 7 and Windows 10, System File Checker is integrated with Windows Resource Protection (WRP), which protects registry keys and folders as well as critical system files. Under Windows Vista, sfc.exe can be used to check specific folder paths, including the Windows folder and the boot folder.
Windows File Protection (WFP) works by registering for notification of file changes in Winlogon. If any changes are detected to a protected system file, the modified file is restored from a cached copy located in a compressed folder at %WinDir%\System32\dllcache.
Windows Resource Protection (WRP) works by setting discretionary access-control lists (DACLs) and access control lists (ACLs) defined for protected resources. If any changes are detected to a protected system file, the modified file is restored from a cached copy located in a folder at %WinDir%\WinSxS\Backup.[3] Permission for full access to modify WRP-protected resources is restricted to the processes using the Windows Modules Installer service (TrustedInstaller.exe). Administrators no longer have full rights to system files.
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