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

 

[Brink]

Thanks again, I've done this before and lost the text. Real organized here:sarc: talk later

Hello Randy,

What do you mean?

 

[DarkPhoenix]

Same version, build, and edition I have. Are you logged into the built-in Administrator account by chance?

Er.. I am not sure. I never liked to use the account called " Administrator". I was under the impression that when I set up windows the default account.. mine.. and only account was the same as the adminstrator account.. but with my name on it..you know.. the name I choose to call the account when I first installed.

The only things I have done to the pc is use a popular tweak tool like Tweak UI - That's not it's name.. I forget it's name at the moment. I'll try to find where I installed it.. LOL

And, I turned off UAC and about 6 different spammy warnings that always pop up by default.. I did this various ways by searching each warning on the Net and some I remember were turned off in Services and ms config.. I don't know if any of that would account for it.

Other things work like that too.. I can type Dxdiag.exe and hit the Enter button and Poof, it opens.

We use the same version, so you should be able to do these things too.. odd that you cannot.. I really wish I knew why so I could tell you.

 

[Brink]

It has to me a combination of the UAC off and/or the Tweak tool. I'll have to do some testing later tonight to see. I have UAC at the top level though.

 

[DarkPhoenix]

It has to me a combination of the UAC off and/or the Tweak tool. I'll have to do some testing later tonight to see. I have UAC at the top level though.

I found the app I was using. It's called Ultimate Windows Tweaker. I had forgot I stuck it off in C drive. I think it just runs by it's executable and does not need to install.. thats why I could not find it. LOL.

Ultimate Windows Tweaker, a TweakUI for Windows 7 & Vista | The Windows Club

 

[Brink]

LOL.

 

[GerryR]

Thanks Shawn,

This is just terrific.

Gerry

 

[James Colbert]

Thanks for the info. Coming to this thread late. Gave it a shot on a laptop here, SFC found corrupted files it couldn't fix. Tried your method (Seeing that it's the same for Vista), but it keeps returning the error:

"Cannot open %windir%\logs\cbs\cbs.log."

I tried changing my security permissions to full control, but still no dice. Any ideas?

This is on a Toshiba L305 series running Vista HP SP1. I'm about to install SP2. Perhaps that will repair the files?

Thanks!

 

[Brink]

Installing the SP2 may be able to. Please post back if not with any other information about it.

 

[James Colbert]

After installing SP2, SFC still returns corrupt files, but nothing seems amiss as far as I can tell, and performance is good. I forgot to run the findstr command, but my feeling is that the results would have been the same.


James

 

[Brink]

Well, if you develop issues from the corrupted files, you could:

• Take ownership of the corrupted files and "Allow" your adminsitrator account "Full Control" of them.
• Extract a good copy of these files from your Vista installation disc to your desktop.
• Replace the corrupted files with the extracted files.

 

[James Colbert]

Well, if you develop issues from the corrupted files, you could:

• Take ownership of the corrupted files and "Allow" your adminsitrator account "Full Control" of them.
• Extract a good copy of these files from your Vista installation disc to your desktop.
• Replace the corrupted files with the extracted files.

Thanks, Brink. After extensive testing, I gave the laptop back to its owner (a neighbor). It ran great and seemed to have no issues. He'll let me know if there are. You likely know this, but I recently learned that just because SFC questions the integrity of some changed files doesn't mean they are 'corrupt'. Running SFC/scannow on one of my Win7 machines (ult 64) resulted in breaking WM (from Vista), which was a minor hack, but not 'corrupt'. SR restored my back to it.

I suppose I'm going to have to find time soon to hunt for an email program I like as much as the old (non-live) WM.

Thanks for your response and the pointers.

James

 

[Brink]

You're welcome James.

Yeah, any change to the file other than default will have it considered to be corrupted.

You can use the tutorial below to use Windows Mail in Windows 7 if you like.

http://www.sevenforums.com/tutorials/5481-windows-mail.html

 

[salimtek]

Thanks Brink for this thread. I was able to solve an error message with it.
I had a problem with a missed dll : msvcp60.dll and the sfc/ scannow command fixed it among other corrupted dll.
Again thank you

 

[Brink]

You're welcome Salimtek, and welcome to Seven Forums.

 

[highmeadowhiker]

I tried it. No TXT file created, it seems.

As best I could, I followed the steps. The command line findstr seemed to tke a very long time. a file search locates no txt file in the recent past. Got a zero length sfcdetails file with no suffix.

The pseudoDOS screen apparently wraps OK; note the spelling of some responses to commands.

Where do I go from here?

 

[Brink]

Hello Highmeadowhiker,

I noticed that in your sfc screenshot.pdf file that you had made mistakes the first time you ran the command below giving you the 0 byte sfcdetails file shown in your other sfc screenshot2.pdf file. However, you did enter the command correctly at the end in your sfc screenshot.pdf file. If you pressed enter for it, do you have a sfcdetails.txt "text file" on your desktop now? If not, then delete the 0 byte sfcdetails file, and try the command below again.

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

 

[goguta]

THX. I'm doing now sfc/scannow. Hope for the best!

 

[njnitehawk]

a question on scf /scannow

is this the program to check for bad sectors on your hard drive?

 

[marsmimar]

SFC checks for missing/corrupt system files and attempts to repair/replace them. For bad sectors you'd want chkdsk.

http://www.sevenforums.com/tutorials/433-disk-check.html

 

[njnitehawk]

disk check

is chkdsk run in the c prompt as well