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

 

[GWT]

Back in the XP days, I used to do the same thing and inevitably I'd have to take out the XP disk and do repairs from the CD drive. I've never had to do that here in Win7, which is strange since after a few months, something should inevitably get broken.

This text file really doesn't tell me much of anything.

 

[Brink]

GWT,

If you like, you could upload and attach the TXT file, and I'd be happy to take a look at it and let you know what it means.

 

[GWT]

Allright. Txt file, attached...

 

[Brink]

Congratulations GWT. The log file shows that SFC did not find any system file errors or corruption.

 

[GWT]

That's surprising since in XP, things broke all the time.

 

[Brink]

LOL, give it time. Any modified system file would be included as needing to be fixed by SFC as well.

 

[Phantomcide]

heya

I'm having an issue with my mpr.dll file which is shown to be corrupted through my cbs.log any pointers as to how i should fix this? I havent been able to install anything new because of it and its getting old fast. Any help would be appreciated =] i've ran sfc /scannow 3 times and it couldnt fix the issue ill try to look into the dvd file extraction fix

 

[Brink]

Hello Phantomcide, and welcome to Seven Forums.

According to your log file you also have a corrupted MPG4DECD.DLL in addition to the mpr.dll file. I have a clean copy of the files from my system in a ZIP file below for eash folder location below. After extracting the files (be sure to only do all of this for one ZIP folder at a time) do step 12 and the yellow TIP box under it in the tutorial below to replace your corrupted copies with the attached ones in each folder location below one at a time.


http://www.sevenforums.com/tutorials/42776-extract-files-windows-7-installation-dvd.html

• C:\Windows\SysWOW64
• C:\Windows\System32

Hope this helps,
Shawn

 

[Phantomcide]

Wow got it to work thanks a million brink your the best btw extremely fast response is deeply appreciated. I only replaced my files in the system32 and didnt understand why it didnt work after the wow64 files got replaced everything seems fine. Thanks again =]

 

[Brink]

You're most welcome Phantomcide. I'm happy to hear that it seems fine again.

 

[GWT]

Brink,

Would not popping in the Windows 7 OS disc and running it off the CD drive do a repair? Like with XP?

 

[Brink]

Hello GWT,

Yes, you could run a SFC scan to repair system files using OPTION ONE in the tutorial.

 

[GWT]

So I have to now boot off the disc now?

I can't just let sfc /scannow run and let it prompt me to insert the disc later on during it's scan?

 

[Brink]

Sorry, you can run a SFC scan at boot or from withing Windows 7, but it will not ask you to insert a disc to replace the files with since that is stored withing Windows 7 instead now unlike in XP.

If the SFC cannot repair or replace a bad system file, then you can use the tutorial below to manually replace the file with a copy from your installation disc.

http://www.sevenforums.com/tutorials/42776-extract-files-windows-7-installation-dvd.html

 

[bgmmancan]

Decent into madness

Brink, sorry to bother you, but after a reinstall of windows 7, my audio failed.

I get a "no audio device found" message while my device manager says that my soundMax card is running fine. I have a hp touchsmart, and noted that the UAA bus driver did not appear in the system devices panel, and thought that a scannow run might fix the problem. however, it returns a message that there is indeed some corrupted files that it cannot fix. But i have no idea how to read the file. I printed the log out and have have tried to attach it, but it is 15 mb in size and i cannot figure out how to send it.


Any help you can give, I'll raise a glass to your health.

thanks, bgm

 

[Brink]

Hello BGM, and welcome to Seven Forums.

If you could do the steps in OPTION THREE of the tutorial to produce the sfcdetails.txt file and upload it, I'll be happy to take a look at it for you.

 

[bgmmancan]

madness ....

Thanks a million. File is attached. Anything funky that can be fouling up my audio?


regards,

bgm

 

[Brink]

BGM,

Looking at your SFC log file, the only file that couldn't be fixed is the file below. It's only a end user license agreement text file that would have no affect on your system or really needed though.

C:\Program Files (x86)\Internet Explorer\en-US\eula.rtf

You might create a new thread in the forum area about your audio issue to see what we can do to help with it.

 

[bgmmancan]

Thanks Brink, will do.

BGM

 

[Brink]

You're welcome.