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

 

[sle3pingz]

Hello sle3pingz,

That would mean that the SFC scan did not find any issues (corrupted or modified) with only your Windows system files.

is that mean nothing corrupted or wrong with my windows system files right?

 

[Brink]

Correct.

 

[sle3pingz]

Correct.

ok , Thanks for you fast respond again Brink ~

 

[Brink]

You're most welcome.

 

[Avie]

System File checker results

Brink,

This is wonderful that you have given so time and knowhow for us all. I will to send in the sickest report.

Best, Avie

 

[Brink]

Hello Avie,

From your log, you have to many to list here, and to try and fix manually. They are just about all corrupted file for Windows Defender and Windows Mail.

I would recommend to do a full scan of your system with Malwarebytes free to help make sure that your system is clean. Afterwards, install and use Microsoft Security Essentials (MSE) that will replace Windows Defender.

Hope this helps,
Shawn

 

[Avie]

File Checker errors

Hey thank you. I ahve done what you suggested and nothing is showing. I had to reinstall WSE this am because I could not find it under programs or control panel

I did find a error to turn on WSE and it will not respond. It is turned off and stays that way. ugh?

 

[Brink]

Do you mean MSE or Windows Defender?

MSE disables Windows Defender since MSE is used instead.

 

[Avie]

Scannow-WSE

I had to reinstall M Sec Essen. It will not turn on in Action Center. Defender is long gone when I removed the service line.

 

[Brink]

What is the "service line" that you removed?

Do you mean that you deleted the "Windows Defender Service"?

 

[Avie]

SFC

What is the "service line" that you removed?

Do you mean that you deleted the "Windows Defender Service"?

Yes I did remove W D service line. However I ran a Karpersky scan and it showed Windows Defender. That would the reason WSE will not turn on.
I still have more than one connection is it seems. IE Firefox default profile is located in Users>Ali>ALLDATA>Roaming. And also in Users>Ali>ALLDATA>local with another profile. Does that make sense?

Yes I did remove W D service line. However I ran a Karpersky scan and it showed Windows Defender. That would the reason WSE will not turn on.
I still have more than one connection is it seems. IE Firefox default profile is located in Users>Ali>ALLDATA>Roaming. And also in Users>Ali>ALLDATA>local with another profile. Does that make sense?

 

[Brink]

If you actually deleted the Windows Defender service in the Services window, then that would be why MSE and Windows Defender is no longer working. That service is required for them to run.

You could try and fix this by doing a system restore using a restore point dated before you deleted the service. If you do not have a restore point available before this happended, then you may need to reinstall Windows 7 to be able to fix this.

 

[Avie]

SFC

I read that was the way to get rid of Windows Defender rather than disabling. I think it was awhile back. I will try. Thank you!!!

 

[Brink]

You're welcome. I hope you have a restore point available for back then.

 

[Avie]

Rstore a faillure

The Win Defender could not read directions and had a error code 2. WSE cannot turn on. Time for reinstall. I fear. Just so fruitless.

 

[Brink]

Yeah, deleting services like that can cause some serious issues.

 

[Avie]

Services done

I really did read to do that. Made sense at the time. I'll get it done. Thanks to your tutorial on the subject. Bless you.

 

[Brink]

Eh, don't sweat it. We all make mistakes.

 

[Avie]

Practice makes perfect!

 

[krash55918]

can't get an elevated command prompt

I am following your instruction by going to start, all programs, accessories, right clicking command prompt and selecting "run as administrator". It takes me to a regular command prompt..C:\Users\Daniel>...according to your instructions...is should read...C:\Windows\system32...what am I doing wrong?