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

 

[karlsnooks]

I was just wondering if they would find it easier to use dism to find the index and then use 7-zip to "open achive" of \sources\install.wim followed by navigating to \n\windows\sytem32\desired file.

In other words, they wouldn't need 7-zip until they got ready for the actual extraction.

Could just be a case of 6 of one and half-a-dozen of the other.

 

[Brink]

I'm not sure if it would make it much easier or not with throwing in additional steps for using the command prompt, but I'll look into it some more tonight to see though.

 

[karlsnooks]

I think you may be correct. I just went thru documenting using Dism and then 7-zip. If i simply stuck to the bare commands and no explanations, then the mix is quicker but to explain takes more when both are used.

 

[karlsnooks]

I'm not sure if it would make it much easier or not with throwing in additional steps for using the command prompt, but I'll look into it some more tonight to see though.

Shawn,
Since I had already installed 7-zip, i found that by:

Navigate to %programfiles%\7-zip
Rt-clk on 7zFM.exe
Choose Run as administrator

works fine. allows me to move/extract files.

also one can choose to pin to start menu, Send to Desktop and then right-click on the result and choose Run as administrator.

 

[Brink]

That would work to run as administrator, but just temporarily until closed unless set in Compatibility Mode. To be honest 7-Zip should of had their program use Run as administrator by default considering how limited it is until you do.

:focus:

 

[dbseven]

Should I or could I extract the files in Install.Wim #3 (Windows 7 Pro) to replace the whole Protected Files Folder, rather than doing a REPAIR INSTALL?

Thanks, Donald

 

[karlsnooks]

No. You will run into ownership and access permission problems plus update related issues.

Replace only the files which SFC has indicated are corrupt.

 

[PocketAcesDMB]

here is my list of corrupt stuff..don't wanna grab and repair the wrong files from the windows 7 dir so im posting to make sure from one of you experts which ones to get

 

[karlsnooks]

This is the file you need to replace:
xchalVx64.sys

 

[PocketAcesDMB]

thanks karl can this be the thing causing my blue screens in my other thread as well ?

 

[karlsnooks]

do not know.

If you have a blue screen problem then:
post in the Crashes and BSOD forum AND
follow the procedure there for posting the info they need.

http://www.sevenforums.com/crashes-debugging/96879-blue-screen-death-bsod-posting-instructions.html

 

[PocketAcesDMB]

do not see this on my win7dvd anywhere else i can grab it running win 7 x64 pro sp1

 

[karlsnooks]

If in Windows Explorer you select your C drive, and then search on xchalVx64.sys what do you find?

I do not have that file installed as a driver to be run on my system, although it is part of my Win 7. I also don't use the capabilities of the driver.

I was afraid of this occurring since \windows\system32 isn't where you find some of the files on your Win 7 DVD, although the end up being installed there.

Now here's another tidbit of info for you: that msg of a hash mismatch can be caused by the copy in sxs being bad and the copy on your computer being good. Maybe Brink knows the best approach to solve your problem.

 

[dbseven]

I need some help:

I read the whole tutorial on using SFC.exe to fix corrupt system files. The bad thing is I think I have over 50. I don't know where to get these files from in the Windows 7 Pro DVD, much less how to put them in the right folders; this seems stupid NOT to have a program to run SFC and parse the c:\windows\Logs\CBS.log to extract the (missing/damaged) file and put it where it needs to. - Donald B.

 

[karlsnooks]

Did you use one of those wonder "tune Up" programs? There is so much missing from the store, the backup copy that Win 7 automatically keeps for you and then uses when needed, that I suspect the use of a "wonder program".

Other than the multitude of missing files from the store, does your system have any problems?

Because unless Brink has some bright ideas, then the only way I see to fix that is a repair install unless you made an image backup before this problem showed up or maybe you are lucky there is a system restore point which will help but I doubt it because system restore depends upon a valid store when it has to restore system files.

 

[dbseven]

I used some freeware registry programs some time ago; I had a broken WMI component, the only way to fix that was repair install. I use AVG PC Tune Up 2011 it is from the same company who make AVG AV I have used for ages. I ran SFC.exe /scannow and it only repairs three files and shows all files repaired at bottom.

BTW: I did a REPAIR INSTALL (Run SETUP during Windows running, with out AV) and got a Boot Screen Menu showing Windows 7 (Repaired). I had to change the Boot Menu with BCDEDIT... Pain in the butt.
Those wonder programs are sometimes crap. I know Windows replaces damaged files it has when it doesn't boot well. If you have any suggestions (a utility that copies all installed programs in Add/Remove List and those in both Program Files(x86) and Program Files, plus those in separate folders with an uninstall###.exe, I would use that to dump this setup and start fresh.
The Windows 7 Forums consideration for this utility and it's promptness is appreciated.
Oh well...Repair install here I come...?
Thanks for the info. Donald

 

[Golden]

Hi,,

I agree with Karl, unless someone else has a better idea. The best option seems to be a Repair Install.

http://www.sevenforums.com/tutorials/3413-repair-install.html

Regards,
Golden

 

[karlsnooks]

Stop using all of those WONDER programs. The safe ones are listed in my sig.

I also recommend the best free, in fact, the best AV software, namely, Microsoft Security Essentials. Once again, link in my sig.

I wish I could stress using MSE enough. MSE is the and the only anti-virus I use and the only anti-virus that I will install on anyone's computer.

 

[PocketAcesDMB]

any uodate regarding that file karl ? it seems to make me think that this could be the reason for my system issue..btw i have download and installed most of your recommended programs ..Do u ever get blue screens regarding memory

 

[karlsnooks]

I get blue screens once every blue moon and the last one was actually a "feature" of a ms office update which was a once only occurrence so couldn't catch it.

If you have blue screens still, then I highly recommend the Crashes and Debugging forum or whatever its called. Those chaps are amazing with much experience and knowledge. Follow the instructions there re posting:
http://www.sevenforums.com/crashes-debugging/96879-blue-screen-death-bsod-posting-instructions.html