How-To Geek

Verify the Integrity of Windows Vista System Files

Windows Vista includes a utility that will scan your system for corrupt, changed or missing system files. Running this from the command prompt is much easier than booting off the dvd into repair mode.

To run this utility, you will need to open a command prompt in administrator mode. You can do that by right clicking the Command Prompt in the list, or by using the nifty keyboard shortcut.

Once you have an administrator command prompt open, you can run the utility by using the following syntax:

[/OFFWINDIR=<offline windows directory> /OFFBOOTDIR=<offline boot directory>]

The most useful command is just to scan immediately, which will scan and attempt to repair any files that are changed or corrupted. You can run that command with this command:

sfc /scannow

Alternatively, you can just choose to verify a particular file, or you can do a verify only, which will check but not repair anything. Here’s an example:

Note that this utility exists for XP as well, but has different options.

Lowell Heddings, better known online as the How-To Geek, spends all his free time bringing you fresh geekery on a daily basis. You can follow him on if you'd like.

  • Published 01/8/07

Comments (26)

  1. Richard

    thanks, great website and very helpful

  2. juancho P

    Great Tip thanks keep in comin’

  3. jules

    i am wandering, if the sfc process takes in account the last Microsoft KB’s, i have installed since
    my xp->vista home premium upgrade?
    As the version of system files could change after the security updates?
    If NO, wont my system files return to previous state (before the Kb updates) and so will i have to reinstall all the kb’s again?
    thanks for advice

  4. Mark

    How do you suggest that I Diagnose and fix the problem when SFC returns that it is unable to fix errors?

    I’m not quite sure what the problem is but a number of DLLs cause errors during startup and Windows Media Center will no start (somewhat fundamental to a Media PC).

    Also Windows Update has failed install kb932539 about 5 times now.

    FYI I’m runnign Vista 64 Home Premium edition.

  5. nick green

    cheers for this saved me alot of hastle with a bad .dll file all fixed now. cheers! great site

  6. whs

    What would be helpful is a way on how to identify the corrupted files – if any. I ran scannow several times and it found corrupted files that it could not fix. Then it gave the path to a log that I was unable to open (access denied). So I was just as smart as before. It would be nice to know how to open this log and have a look at what’s corrupted.

  7. breps

    thanks for this, it helped me out big time! I was about to load in the vista disk and do a reboot.

    WHS – you probably need to try opening the log file with a program that is running under an administrator account.

    Try running notepad as an administrator, then open the log file with ” File > Open “.

  8. Mike

    You guys are awesome! I use a celeron running vista. Is there a way I can make her go faster. Software or some tweak I can do on em?

  9. Glen

    Mike – put your computer in a car and take it for a drive – voila! it’s faster!!

  10. Chad

    If you want to know which files were corrupted and could not be repaired, open up CBS.log (default location is C:\WINDOWS\Logs\CBS\cbs.log) and scroll all the way to the bottom. Search for the following phrase: “Cannot repair member file”, search direction bottom to top. Remember to check the date stamp on the files.

    If the corrupted file is one you’ve modified yourself, such as config.sys, you can probably ignore the result. Or, if you’re really concerned about it, or you think it could be causing problems, simply manually undo any changes.

    Mike, you might take a look at, they have several articles listing ways to tweak your system’s performance. You won’t suddenly be running a fire-breathing gaming machine but in many cases the improvements are noticeable.

  11. mary

    For 2 days been trying to reinstall xp os..gets stuck when gets to first verifying drive integrity. Got to 50% last night but always flips back to 0%. How do I figure out how to naually get it past this portion or, correct the problem that I cannot figure out exists. Obviously something is preventing me from moving forward/completing the verification of drive integrity. Please help!

  12. sbw07

    To see which files SFC was unable to repair open an Administrator’s cmd.exe and type
    findstr /C:”[SR] Cannot repair member file” %windir%\logs\cbs\cbs.log >sfcdetails.txt
    as stated in this microsoft article .
    Then open C:\Windows\System32\sfcdetails.txt and you’ll see a listing of the files which remain unrepaired.

    To repair them follow the instructions in that article. You’ll need a good copy of the problematic files to restore them from, so you might need to copy them off your Vista DVD. To find out how, check out

  13. Ian

    Has anyone looked at whether you can run this from a dos prompt outside of Vista? I.e. to fix system files that are usually locked with the OS running?

  14. Chris

    Outstanding information! The utility found corrupt files on my system, repaired them, and now the system is running better. Hopefully I won’t have to format to get rid of previous malware now. Thanks a ton!

  15. ron

    how can I find out my beginning sector and ending sector of my hard drive? what I am trying to accomplish is to run a scan of the integrity of my sectors and the software that I am using is by flobo
    and of course I have to input the beginning sector and the ending sector, so that it knows how big my hard drive actually is. How can I find out this information?

  16. Shari

    A THOUSAND THANKS!! Since mid-April, I’ve spent long nights searching for why flashplayer suddenly stopped working after we updated it to the latest version. Since lots of users are having this problem, it’s too bad Adobe won’t admit their update is breaking driver files, & save us from weeks of frustrating searching & nonworking fixes. I’ve been up some nights until 3am—despite having to get up the next morning at 7:00 for work.

    Luckily, last week—the fourth week of my frustrating search—I found a few posters who recommended copying a good msacm32.drv file from another vista pc. But, I don’t know anyone else unfortunate enough to be using vista, so that wasn’t an option. However, those posters put me on the right search path—instead of searching for fixes for missing registry entries, I began searching for bad driver fixes.

    So a few days ago, I used “msacm32.drv” as a search keyword. This gave me your page in the results. Your fix is dramatically different from other fixes I’d found, so I was cautiously optimistic. I was afraid that if your fix didn’t work, we’d have to take the pc to BestBuy. Because they’ve wiped out our files before—when trying to fix something else—& yet still charged us for their “services”, I really didn’t want to go to BestBuy. That’s why I’m even more grateful that you’ve posted this right-on solution. Again, thank you a thousand times.

    Now I can go back to listening to jazz greats on youtube, & learning to incorporate their style into my jazz piano!


  17. BG


    Thank you for info on windows integrity checking. I have Vista 32-bit with some corrupted files. Was following your advise with running “SFC /scannow”. Got to “Verification 68% complete” and received the following message:
    “Windows Resource Protection could not perform the requested operation”.

    Then tried to view CBS log file as suggested by Chad and received “Access is denied”.

    Please advice.

    Thank you.

  18. micheal

    I own an acer aspire 5515 been having problems with it and acer idea to fix windows is factory default restore. files still damage. having problems with start up and shutting down. tried to upgrade frome home basic to home premium and autoplay doesnt work any times windows doesnt load then pops up launch windows repair. and it doesnt do any thing, cause acer took that out. will the command prompt work on my acer aspire. will it fix the problems im having.

  19. Jack

    I have Vista Home Basic . When I run System File Checker as administrator the verification proceeds to 76% then “Windows Resource Protection could not perform the requested operation”.

    Then tried to view CBS log file as suggested by Chad and received “Access is denied”.

    Could you please advise


  20. Marko

    Will it repair system files modified/infected by VIRUS also?

    Thank you.

  21. Marko

    Thanks, no answer. I’ll forget I asked this…

  22. Marko - Reply

    @Marko – it should replace them if they were modified by virus or otherwise.

  23. Amit

    my computer is not able to boot, it gives msg as follows

    File: \ windows\system32\config\system
    Status: 0xc000014c
    Info: windows failed to load beacuse the system registry file is missing, or corrupt

    it asks me to insert the operating system CD/DVD and further repair the operating system, however when i do the same (by putting in my DVD and F8 )

    it says that,

    BOOTMGR image is corrupt. The system cannot boot.
    Plz help

  24. Anonymous

    XP’s SFC cmd seems to have no “verify only” options.
    Or does it?

    Will a Vista (or W7) SFC cmd work on XP?

  25. mike

    help i have to run computer in safe mode .wont run normal mode windows freezes up

  26. mike


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