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

 

[shadowminx69]

would it be a bad Idea to make a task to run this each night? not sure if it would be a good Idea or not. Hit me back

 

[Romulinx2]

Thanks, I forgot about this. I used to use it in early editions of windows. Run it and sorted some errors.

 

[darkassain]

would it be a bad Idea to make a task to run this each night? not sure if it would be a good Idea or not. Hit me back

you shouldnt have any problem with it...

 

[Brink]

Thanks, I forgot about this. I used to use it in early editions of windows. Run it and sorted some errors.

You're welcome Romulinx2.

Shawn

 

[thunder2008]

Very useful information running the sfc atm, thank you for this thread.

 

[Brink]

You're welcome Thunder2008.

 

[anykey]

Good to see this again.
Thanks for the reminder.

Didn't you used to put some letters/codes as a suffix, something such as /* or /?. This was to fix things.

 

[Brink]

Hello Anykey,

You could type sfc /? in the elevated command prompt for a complete list of sfc commands to use, but sfc /scannow is the best option to scan and repair all protected system files command. No other suffixes that I know of though.

 

[anykey]

Thanks Brink, perhaps I am thinking of the old chkdsk.
I was always taught to do it something like this:

chkdsk /f /r /v /e

 

[Brink]

Yeah, that would for chkdsk then.

Not sure the /e extension is available in Vista or Windows 7 or what it is for though.

 

[bluemoon4ever]

i have a couple of problems with SFC ...

1) when i run it from a Admin Command Prompt from within Windows the program runs ok and finds errors (windows Media Player i think), but it says "Windows Resource Protection found corrupt files but was unable to fix some of them.
Details are included in the CBS.Log windir\Logs\CBS\CBS.log. For example" ... which is just double dutch to me.

2) When i try and run it from the command prompt when booting from the System repair disk i get the error: SFC has a repair pending, please re-boot to finish the repair (or something like that) and when i reboot and try again i still get the same error. this also happens when i boot from hard disk and press F8 and choose repair from the boot menu.

either way i cant repair the system files ... any ideas?

 

[jfar]

Hi, did you try a fresh install, it may sort your problem out.

 

[zigzag3143]

i have a couple of problems with SFC ...

1) when i run it from a Admin Command Prompt from within Windows the program runs ok and finds errors (windows Media Player i think), but it says "Windows Resource Protection found corrupt files but was unable to fix some of them.
Details are included in the CBS.Log windir\Logs\CBS\CBS.log. For example" ... which is just double dutch to me.

2) When i try and run it from the command prompt when booting from the System repair disk i get the error: SFC has a repair pending, please re-boot to finish the repair (or something like that) and when i reboot and try again i still get the same error. this also happens when i boot from hard disk and press F8 and choose repair from the boot menu.

either way i cant repair the system files ... any ideas?

BM

SFC verifies the system files and fixes those it can fix. If there is a corrupt file , or a missing file that isnt in the stored files it cant replace it. If you view the cbs.log file it will tell you which and if you have troubles upload it to us and we will give you a hand.

In the final analysis jfar is right. A clean install is going to be the fastest easiest way to get rid of all the problems.
Is there something on this drive which you cannot live without?

Ken

 

[bluemoon4ever]

i have a couple of problems with SFC ...

1) when i run it from a Admin Command Prompt from within Windows the program runs ok and finds errors (windows Media Player i think), but it says "Windows Resource Protection found corrupt files but was unable to fix some of them.
Details are included in the CBS.Log windir\Logs\CBS\CBS.log. For example" ... which is just double dutch to me.

2) When i try and run it from the command prompt when booting from the System repair disk i get the error: SFC has a repair pending, please re-boot to finish the repair (or something like that) and when i reboot and try again i still get the same error. this also happens when i boot from hard disk and press F8 and choose repair from the boot menu.

either way i cant repair the system files ... any ideas?

BM

SFC verifies the system files and fixes those it can fix. If there is a corrupt file , or a missing file that isnt in the stored files it cant replace it. If you view the cbs.log file it will tell you which and if you have troubles upload it to us and we will give you a hand.

In the final analysis jfar is right. A clean install is going to be the fastest easiest way to get rid of all the problems.
Is there something on this drive which you cannot live without?

Ken

hi guys. i would rather not do a clean install as its taken me a few weeks to get Windows 7 just as i like it and would hate to start all over again.

i have attached the latest CBS.LOG here. Hope you can make some sense of it lol.

thanks again for your help.

 

[sunnystaines]

what was wrong with the simple goto run then sfc /scannow and place the windows disc in the drive or can that not be done in w7, helped fix quiet a bit in xp & w98 days.

 

[Brink]

Hello Sunny,

It is no longer required to have to insert the installation disc since the system files are stored within Windows 7 and Vista to replace the corrupted ones with. That's all.

 

[sunnystaines]

Brink

thanks did not know that, can you still run it from the run box?

 

[Brink]

Sorry, but no. It needs to run through a elevated (run as administrator) command prompt instead.

 

[sunnystaines]

brink

thanks