Run System File Checker (SFC)

System File Checker checks that all Windows files are where they should be and that they are uncorrupted. This works in all modern versions of Windows including Vista, Windows 7, and Windows 8. If you’ve done all your virus and spyware checking, error checking and defragging, and Windows is still doing strange things, then SFC can avoid a reinstall.

1. Open a Command Window in Administrator mode. Please note that Windows 8 users will need a few extra steps.

* click Start
* click All Programs, then Accessories
* right click on the Command Prompt option,
* on the drop down menu which appears, click on the Run as Administrator option.
* If you have not disabled User Account Control, you will be asked for authorisation. Click the Continue button if you are the administrator or insert the administrator password.

2. Start the System File Checker

* In the Command Prompt window, type: sfc /scannow
* press Enter.
* You will see โ€œthe system scan will beginโ€ message.

The scan may take some time and windows will repair/replace any corrupt or missing files. You will be asked to insert your Windows CD or DVD if itโ€™s needed.

Close the Command Prompt Window when the job is finished.

The Conversation

Follow the reactions below and share your own thoughts.

  • I remember XP used to perform a system file check during a reboot as well (to schedule a file scan before Windows boots up). Is there a way to do that with Vista?

  • sparky

    Love this thanks alot im a very tech savy guy but i wasnt sure if vista had kept this lovely feature and now i know and didnt have to open command prompt lol (lazy i know)

  • joy

    when try to run sfc /scannow it says windows resource potection could not start the repair service. Wat can i do

    • Ken Gateman

      > I ran the sfc file ! When it finished I got the following reply …
      “Verification 100% complete.
      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

      When I tried to open this file I rec’d a message saying access denied !
      What can I do now ?

      • Confused

        Same here… Cannot read the results.
        Have changed the ownership in properties of the log file , looked for internet site to decode… no solution.
        Some files; but cannot see them to get a solution? How weird is that?>

  • xrays

    Thanx for help

  • xrays

    Joy … make a mug of tea and relax … then try the same way above and don’t forget to RUN IT AS ADMINISTRATOR :))))

  • Jean

    What if I only have recovery disks – HP doesn’t provide Windows CDs – you make your own recovery disks? Should I still run system file checker?

    • Anonymous

      did you ever get an answerer??

  • Exelle

    when all else fails ๐Ÿ˜€

    (running vista32 home premium on a vaio laptop)

    sorry to say, I was careless and got a virus. a nasty one – couldn’t open my task manager, not even in safe mode. when I tried opening it (in several various ways), all I got was a dead icon of the task manager in the taskbar, next to the watch. and by dead, I mean it didn’t even show the CPU usage like it did.

    so: I tried bitdefender – found my computer to be clean. I tried also stinger from mcafee – cute little fellow, said the same thing about my computer. I then tried malwarebytes – same result.

    I tried booting into safe mode… there, nothing worked, just about anything I tried led to my PC to stall indefinitely.

    after all this, I ran from link to link into this one. ran the “sfc /scannow” command in safe mode and after restarting, my computer was noticeably faster than before ๐Ÿ™‚ but the task manager still didn’t run.

    the last thing I did after this was a system restore to a point earlier in the day. this definitely solved my problem, and now I’m running “sfc /scannow” to speed up my pc again ๐Ÿ™‚

  • passerby

    In the end it says:
    Windows Resource Protection found corrupt files but was unable to fix some of them. Details are included in the CBS.Log windirLogsCBSCBS.Log….

    Didn’t ask for any windows cd/dvd.
    What should the next step be?

    • sandy

      hi i have the same problem and dont no much about computers r u able to help me what did u do to fix urs

      • sandy


  • Andy

    – Thank you very much.

  • Andy

    – passerby – copy everything to DVD and reinstall the OS – shouldn’t take longer than few hours – and nothing’s better than a fresh OS…

  • Brent

    My computer came with Vista, how can I put the CD or DVD in if it asks?

  • Anonymous

    When i done the following scan

    System File Checker
    by command promt sfc scannow
    It 100 % complet
    It Reply
    Windows Resource Protection did not find any integrity violations!

  • Joanna

    what if you’ve done this and got ‘Windows Resource Protection did not find any integrity issues’?

  • Anonymous

    Scan went to 4% and then I received the following message.
    “Windows Resource Protection could not perform the requsted operation”
    Please help.
    Thank you.

  • Anonymous

    I have done this but get the error message:

    “The pipe state is invalid”

  • nikita

    Me have sshnas21.dll eror what to do?

  • Saurabhsameer

    thanku so much………………………………………………………………

    • crzybkr

      when i run sfc/scannow i get to 82% and get the msg windows resource protectio could not perform the requested operation. my system was running fine until i installed vista sp2. now the shadowcopy/restore is not operating, and will not switch on. also my skype freezes up the pc when i start it up. i have uninstalled and reinstalled and updated it several times.

      • crzybkr

        well i had to a complete reinstall of the system to fix my error. seems to work fine now

  • umar

    the only problem is, is that i dont have a vista CD if it asks for one

  • Bebe3254

    I couldn’t run the sfc /scannow because it kept saying parameters incorrect. In fact I couldn’t run any downloaded exe file without getting that same message. So I took a chance and disable user account control and I did my first sfc scan. Now I will be able to fix my computer. Thank you for the info on sfc

  • Cherish.jcs

    i ran it and it said it found corrupt files but couldn’t fix some of them.. what do i do now? help pls

  • Pascal

    Anybody know how to fix this:

    Itunes was not installed correctly. Please reinstall iTunes. Error 7 (Windows error 193)

    and after x reinstal and sfc /scannow still have this problem .-(

    • Andy932


      • Tracy

        > I got the CBS.log error and when I tried to enter it to look at the log got this error “Access is denied”. I do not get a drop down in accessories to ‘run as administrator’. Why aren’t I the administrator on my own computer. I hate Vista.

  • Kyrizzman1

    Vista is the issue, has many issues that do not exist in other MS OS. Sorry as sorry can be that I went for it. Vista Home Premium

    • stimpy-bluenose

      Me too, I really had no idea about the preloaded programme business, I did not expect to have to buy Vista twice, I regret buying it once!

  • stimpy-bluenose

    I’m so disappointed with Vista Home Premium. I’m running the 64 bit. I’ve had problems with Windows Installer and I can’t open my word documents, iTunes, and a number of other programs. Apparently Windows Installer has corrupted. I’ve tried asking Microsoft for help but all I get told is reinstall Vista from a CD or DVD. Trouble is, my HP desktop PC came preloaded and I am getting nowhere fast with both HP and Microsoft, just instructions to buy or borrow a either a Windows Vista Disc or from a recovery disc. I’ve seen quite a few problems like mine posted in various forums, one of them had a very sarky answer from someone who said he is a a microsoft engineer saying it wasn’t his fault if the person with the problem couldn’t borrow a Windows Vista CD!! Way to go Microsoft!! Customer service obviously is a high priority with you.

  • Rich


    Don’t get upset at Microsoft, just hit the F11 key when your computer is booting. You will access a very nice recovery program that HP has put on your system. They have a non-destructive recovery option that will reinstall all your system files but won’t delete any of your data. All you will need to do is reinstall any programs you have put on since you got the computer.

  • Www Thani

    When i done the following scan
    it come like

    System File Checker
    by command promt sfc scannow
    Microsoft Windows [Version 6.0.6002]
    Copyright (c) 2006 Microsoft Corporation. All rights reserved.


    Beginning system scan. This process will take some time.

    Beginning verification phase of system scan.
    Verification 100% complete.
    Windows Resource Protection found corrupt files but was unable to fix some of th
    Details are included in the CBS.Log windirLogsCBSCBS.log. For example

    what should i do …..

  • astrid

    @ www Thani, I have the same problem.

    Anyone who can help me with this????

  • beerslayer

    What I want to know, before trying any of this, is whether the ‘sfc /scannow’ command can be UNdone by running a System Restore. My 64-bit Vista OS is a house of cards right now and I’m terrified of making it worse. I’d like to see if this command could help stabilize it a bit but I want to be sure I can undo whatever it does if it makes things worse.

  • @ beerslayer,
    It’s highly unlikely to make things worse. It’s very likely to improve things. System Restore is a last ditch resort which is great if it works. In my experience the more dire the need the less likely it is to work.

    I avoid all these problems by using imagaing software.

  • @ thani and astrid

    It often helps to run SFC from Safe Mode.


  • Bill C

    Corrupt files CBS\.log windir\logs What a nice scan, did not take that long and found a serious problem quickly.

    Thank You

  • Debra

    What Vista DVD?

    I’m on my fourth PC and I’ve never received a DVD from Microsoft upon purchase, so, what DVD are you talking about???

    I guess I can’t use SFC then?


  • Sassylady

    Yes, you can run sfc if you don’t have a disc. I don’t have any disc, but sfc fixed my problems after I got a virus or malware downloading a free video downloader. I still can’t boot to safe mode and have tried F8 and other fixes to get into safe mode “scare me” too much. I am going to leave things alone at this point as computer seems to being working fine other than iexplore.exe freezes when running internet explorer.

  • Sassylady

    I have a 64 bit system, Windows 7 which has bot 32 and 64 bit internet explorer. When I go to command prompt and get ready to fun sfc it comes up as C:…system32\ Should I be able to run sfc on C:…system64\ since it is a 64 bit system? And if so, do I just change the last 2 digits from 32 to 64 and type in sfc scannow?

  • Sassylady

    Further research tells me that at the C: prompt when it says C:…system32\ and your type in sfc/scannowhat it checks both the 32 and the 64 bit files. Is that correct? Thank you for your time.

  • 75FXE

    Have a corruption of Vista Home Premium unable to solve with system restore, returning to prior saved backup. Keep getting message that windows is not accepting control instructions or that host process has stopped working. When trying to use sfc, the “not accepting control messages prevents me from using. Trying to diacle user controls is likewise blocked as is ccleaner. Malwarebytes Antimalware 1.6 showed no infection but wouldn’t allow me to update its definitions. Much of my functions are either blocked by refusing commands or run more slowly than a 286 cpu. Suggestions? Oh, and the glitch also turned off my anti-virus shields in Avast, and refuses ability to turn them on so I’m reluctant to visit websites.

    • Alan Vallis

      Have you tried running SFC in Safe Mode?>

  • brent

    HELP ME!! you are my best bet ,,i have been trying for a tear and year …windows resorce found to be corrupt when i did the scan ,,it was able to fix some but not all ,,SO What now ,,and please keep it simple ,,i am not a geeek Brent

  • Jack

    I have after sfc /scannow: “Windows Resource Protection found corrupt files but was unable to fix some of them.”

    I have this error message 3 years already when running sfc /scannow. The log shows a lot of corrupt files all with the name desktop.ini but these files can be deleted without problems… so it is a windows shit!
    I think there is no reason to make any steps while the sytem is working well…

  • tom

    im not through running it yet but thank you

  • michael baransky

    followed instructions but when I opened command prompt drop down box did not appear could not run as administrator

  • charles davis

    thank you for the direction. i do have conflicting programs on my computer that need to be cleaned up. thanks again…chuck

  • meme

    How do you know that it’s working?

  • Jer

    i tried in sfc mode but it not working there too . and what about pendinddelete and pendingrename , i read that on microsoft official site you must have this 2 folders in %WinDir%\WinSxS\Temp but there is not pendingdelete so what to do .

    • col

      I have tried the same – when I take ownership of Temp folder and creat new folder when I rename it asks if I want to merge with existing folder ?????

  • Chris Johnson

    I resolved a problem with Windows Live Mail that I was having, one of which Microsoft did not know the answer to. “Find Message” in Windows Live Mail does not work no matter what information you type in. The cause of the problem is shared problems, unshared all programs by clicking “Share with nobody” and find message works!!! I hope this info helps someone, this same problem has been posted on the internet by many people.

  • Chris Johnson

    I mistyped my email this is the correct one: