SFC /SCANNOW Command - System File Checker

How to Repair Windows 7 System Files with System File Checker​

   Information

The sfc /scannow command (System File Checker) scans the integrity of all protected Windows 7 system files and replaces incorrect corrupted, changed/modified, or damaged versions with the correct versions if possible.

   Tip

If you get the Windows Resource Protection Could Not Start the Repair Service error when trying to run SFC, then make sure that the Windows Modules Installer service is enabled, click on Start, and set to Manual.

Services - Start or Disable

OR

Copy and paste the command below in the elevated command prompt, and press Enter. After the Windows Modules Installer service has started, try running the SFC command again

net start trustedinstaller

   Note

The KB3022345, KB3035583, and KB3068708 updates will cause SFC to give you a false mismatch message in SFC for files related to these updates.

You can safely ignore these results in your SFC details since it will not affect SFC from being able to repair other system files.

   Warning

Be aware that if you have modified your system files as in theming explorer/system files, running sfc /scannow will revert the system files such as explorer.exe back to it's default state. Make the appropriate backups of your system files that you have modified for theming if you wish to save them before running sfc /scannow.

:note: For the updated Windows 10 tutorial, please see - SFC Command - Run in Windows 10 - Windows 10 Tutorials

CONTENTS:

• Option One: To Run the SFC /SCANNOW Command at Boot
• Option Two: To Run the SFC /SCANNOW Command in Windows 7
• Option Three: How to See and Read Only the "SFC" Scan Results from the CBS.LOG

OPTION ONE

To Run the SFC /SCANNOW Command at Boot

1. For how, see METHOD TWO at this link: SFC /SCANNOW : Run in Command Prompt at Boot

   Note

Using OPTION TWO below is recommended if able.

If you would like to get help with your SFC issue, then be sure to upload and attach your sfcdetails.txt file from OPTION THREE below in your post.

OPTION TWO

To Run the SFC /SCANNOW Command in Windows 7

1. Open an elevated command prompt or an elevated PowerShell, and do step 2 or 3 below for what type of scan you would like to run.


2. To Scan and Repair System Files
NOTE: Scans the integrity of all protected system files and repairs the system files if needed. Please see red WARNING box at the top of this tutorial.
A) In the elevated command prompt, type sfc /scannow, press Enter, and go to step 4 below. (see screenshot below)
NOTE: This may take a little bit to finish.


3. To Only Verify if the System Files are Corrupted
NOTE: Scans and only verifies the integrity of all proteced system files only. This command will not change your system files as in the red WARNING box at the top of this tutorial.
A) In the elevated command prompt, type sfc /verifyonly, press Enter, and go to step 4 below.
4. When the scan is complete, hopefully you will see all is ok like the screenshot below.

   Note

• If SFC could not fix something, then run the command again to see if it may be able to the next time. Sometimes it may take running the sfc /scannow command 3 or more times to completely fix everything that it's able to.
• If not, then download and run the 32-bit (x86) or 64-bit (x64) System Update Readiness Tool for your same installed 32-bit or 64-bit Windows 7, restart the PC afterwards, and try the sfc /scannow command again.
• If still not, then try using OPTION ONE above to run the sfc /scannow command at boot.
• If still not, then you can attempt to run a System Restore using a restore point dated before the bad file occured to fix it. You may need to repeat doing a System Restore until you find a older restore point that may work.
• If still not, then you can use the steps in the TIP box in the OPTION THREE section below to manually replace the files that SFC could not fix if there are not to many fix.
• If there are to many files to manually fix, or you prefer not to use OPTION THREE below, then you could do a repair install without losing anything.

If you would like to get help with your SFC issue, then be sure to upload and attach your sfcdetails.txt file from OPTION THREE below in your post.

5. When done, close the elevated command prompt.

OPTION THREE

How to See and Read Only the "SFC" Scan Results from the CBS.LOG

   Note

When SFC runs, it logs it's actions into the C:\Windows\Logs\CBS\CBS.log. The steps in this option will show you how to see only the specific SFC entries with the [SR] tags in this CBS.log. This can be helpful to show you what files SFC could not fix automatically if you wanted to try and manually replace them.

1. Open an "elevated command prompt" (right click -> Run as administrator).

2. In the elevated command prompt, copy and paste the command below, and press Enter. (See screenshot below)
NOTE: This will place a sfcdetails.txt file on your desktop with only the SFC scan result details from the CBS.LOG in it.

findstr /c:"[SR]" %windir%\Logs\CBS\CBS.log >"%userprofile%\Desktop\sfcdetails.txt"

3. Close the elevated command prompt.

4. Open the sfcdetails.txt file on your desktop to see the SFC scan details in the CBS.LOG.

5. You can safely delete the sfcdetails.txt file afterwards if you like.

   Tip

If you need to replace a corrupted system file that SFC cannot fix, then this will show you how to by extracting a new copy directly from your Windows 7 installation DVD.

Extract Files from Windows 7 Installation DVD

That's it,
Shawn

Related Tutorials

---

• How to Run the System File Checker in a Command Prompt at Boot
• How to Do a System Restore in Windows 7
• How to Do a Repair Install to Fix Windows 7
• How to Run Disk Check in Windows 7
• How to See Windows 7 Reliability and Problem History with Reliability Monitor
• How to Extract Files from the Windows 7 Installation DVD
• How to Troubleshoot a Problem by Performing a Clean Startup in Windows 7 or Vista

 

[marshallslion]

Thanks Brink!
Hadn't heard of this. lol

 

[Brink]

You're most welcome Marshallslion, and welcome to Seven Forums.

 

[gamer dude]

I tried sfc /verifyonly but it said "YOU MUST BE AN ADMINISTRATOR RUNNING A CONSOLE SESSION IN ORDER TO USE THE SFC UTILITY"

but i am the admin. help?

+rep

 

[Brink]

Hello Gamer dude,

It just means that you will have to right click on the cmd shortcut and click on "Run as administrator" first, then type in the command.

1. Open a elevated command prompt (right click -> Run as administrator).

 

[gamer dude]

Thanks for the quick reply Brink

 

[Brink]

You're welcome mate.

 

[enrell]

after running /scannow now i found out that they cant repair my Ati and Nvidia files but funny thing is at the end of the log, it says "All files and registry keys listed in this transaction have been successfully repaired"

i have no problem with the files and my gpu is working fine.

i have attached the sfcdetails file. please have a look and maybe you guys can shed a light on this.

tanx !!

 

[marsmimar]

after running /scannow now i found out that they cant repair my Ati and Nvidia files but funny thing is at the end of the log, it says "All files and registry keys listed in this transaction have been successfully repaired"

i have no problem with the files and my gpu is working fine.

i have attached the sfcdetails file. please have a look and maybe you guys can shed a light on this.

tanx !!

Hello enrell and welcome to Seven Forums.

As the information section at the beginning of the tutorial says, "The sfc /scannow command (System File Checker) scans the integrity of all protected Windows 7 system files and replaces incorrect corrupted, changed, or damaged versions with the correct versions if possible." I might be mistaken but I don't believe SFC will check the hardware that might be installed on a given computer. You might have to go to Device Manager. Device Manager can be used for changing hardware configuration options, managing drivers, disabling and enabling hardware, identifying conflicts between hardware devices, etc.

Open Device Manager

 

[enrell]

after running /scannow now i found out that they cant repair my Ati and Nvidia files but funny thing is at the end of the log, it says "All files and registry keys listed in this transaction have been successfully repaired"

i have no problem with the files and my gpu is working fine.

i have attached the sfcdetails file. please have a look and maybe you guys can shed a light on this.

tanx !!

Hello enrell and welcome to Seven Forums.

As the information section at the beginning of the tutorial says, "The sfc /scannow command (System File Checker) scans the integrity of all protected Windows 7 system files and replaces incorrect corrupted, changed, or damaged versions with the correct versions if possible." I might be mistaken but I don't believe SFC will check the hardware that might be installed on a given computer. You might have to go to Device Manager. Device Manager can be used for changing hardware configuration options, managing drivers, disabling and enabling hardware, identifying conflicts between hardware devices, etc.

Open Device Manager

hi there

what i meant the errors are graphic drivers..ati and nvidia drivers..but funny thing is i dont have any error when using my gpu..

 

[niemiro]

after running /scannow now i found out that they cant repair my Ati and Nvidia files but funny thing is at the end of the log, it says "All files and registry keys listed in this transaction have been successfully repaired"

i have no problem with the files and my gpu is working fine.

i have attached the sfcdetails file. please have a look and maybe you guys can shed a light on this.

tanx !!

Hello enrell and welcome to Seven Forums.

As the information section at the beginning of the tutorial says, "The sfc /scannow command (System File Checker) scans the integrity of all protected Windows 7 system files and replaces incorrect corrupted, changed, or damaged versions with the correct versions if possible." I might be mistaken but I don't believe SFC will check the hardware that might be installed on a given computer. You might have to go to Device Manager. Device Manager can be used for changing hardware configuration options, managing drivers, disabling and enabling hardware, identifying conflicts between hardware devices, etc.

Open Device Manager

hi there

what i meant the errors are graphic drivers..ati and nvidia drivers..but funny thing is i dont have any error when using my gpu..

Hello!

Have you ever used Driver Sweeper? There was a bug in Driver Sweeper which caused this problem. Do you still have it installed? Are these files in the backup directory?

Thanks a lot!

 

[enrell]

Hello enrell and welcome to Seven Forums.

As the information section at the beginning of the tutorial says, "The sfc /scannow command (System File Checker) scans the integrity of all protected Windows 7 system files and replaces incorrect corrupted, changed, or damaged versions with the correct versions if possible." I might be mistaken but I don't believe SFC will check the hardware that might be installed on a given computer. You might have to go to Device Manager. Device Manager can be used for changing hardware configuration options, managing drivers, disabling and enabling hardware, identifying conflicts between hardware devices, etc.

Open Device Manager

hi there

what i meant the errors are graphic drivers..ati and nvidia drivers..but funny thing is i dont have any error when using my gpu..

Hello!

Have you ever used Driver Sweeper? There was a bug in Driver Sweeper which caused this problem. Do you still have it installed? Are these files in the backup directory?

Thanks a lot!

yeah..there were an issue when previous version of the DS accidentally removed ati files which are needed for the SP1. I have since upgraded to the latest version.

mmmm...so if i can find those files, i just copy and paste to the specific directory?

 

[Brink]

Hello Enroll, and welcome to Seven Forums.

Reinstalling or installing the latest ATI/AMD drivers should have replaced and fixed the damaged/missing files.

 

[karlsnooks]

Shawn,
Here's a link to a new kb on sfc. Don't know whether you think some of the info should/needs to be integrated into the tutorial.

How to use the System File Checker tool to troubleshoot missing or corrupted system files on Windows Vista or on Windows 7

 

[Brink]

Thank you Karl, but the tutorial already covered everything in it and more.

 

[karlsnooks]

Shawn,
I didn't remember seeing the part in the tutorial regarding taking ownership, setting access rights and then replacing the bad file.
karl

 

[Brink]

The yellow TIP box is for that with more details on how at the link in it.

 

[karlsnooks]

The yellow TIP box is for that with more details on how at the link in it.

My error. I overlooked the TIP box. Thanks for point it out.
karl

 

[Brink]

It's no problem Karl. Thank you again.

 

[karlsnooks]

Shawn,

What do you think of using DISM to determine the index into the Wim file?

 [B][U]USE DISM TO DETERMINE INDEX INTO WIM FILE[/U][/B]

   
   
  [B][U]32 BIT WIN 7[/U][/B]

  C:\Windows\system32>dism /get-wiminfo /wimfile:e:\sources\install.wim
   
  Deployment Image Servicing and Management tool
  Version: 6.1.7600.16385
   
  Details for image : e:\sources\install.wim
   
  Index : 1
  Name : Windows 7 STARTER
  Description : Windows 7 STARTER
  Size : 8,072,604,598 bytes
   
  Index : 2
  Name : Windows 7 HOMEBASIC
  Description : Windows 7 HOMEBASIC
  Size : 8,125,226,573 bytes
   
  Index : 3
  Name : Windows 7 HOMEPREMIUM
  Description : Windows 7 HOMEPREMIUM
  Size : 8,566,642,846 bytes
   
  Index : 4
  Name : Windows 7 PROFESSIONAL
  Description : Windows 7 PROFESSIONAL
  Size : 8,447,825,392 bytes
   
  Index : 5
  Name : Windows 7 ULTIMATE
  Description : Windows 7 ULTIMATE
  Size : 8,607,765,255 bytes
   
  The operation completed successfully.
   
   
  [B][U]64 bit Win 7[/U][/B]

   
  C:\Windows\system32>dism /get-wiminfo /wimfile:e:\sources\install.wim
   
  Deployment Image Servicing and Management tool
  Version: 6.1.7600.16385
   
  Details for image : e:\sources\install.wim
   
  Index : 1
  Name : Windows 7 HOMEBASIC
  Description : Windows 7 HOMEBASIC
  Size : 11,710,161,360 bytes
   
  Index : 2
  Name : Windows 7 HOMEPREMIUM
  Description : Windows 7 HOMEPREMIUM
  Size : 12,222,587,449 bytes
   
  Index : 3
  Name : Windows 7 PROFESSIONAL
  Description : Windows 7 PROFESSIONAL
  Size : 12,122,886,417 bytes
   
  Index : 4
  Name : Windows 7 ULTIMATE
  Description : Windows 7 ULTIMATE
  Size : 12,285,492,779 bytes
   
  The operation completed successfully.

 

[Brink]

Karl,

It's another good option. I only used what I had at steps 8-10 here since they already had the WIM opened in 7-Zip ready for extraction.