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How Do I Fix a CRC Error When I Try to Copy a File?

A Cyclic Redundancy Check error usually means there’s a problem with your hard drive.

CRC errors happen when there's a bad spot on the media of your hard disk. Data recovery and disk repair are often possible with the right tools -- but you won't need them if you have a backup.
Digital Error
Question: Outlook started acting up, so as part of my attempts to fix it I tried to copy the PST to another location. The copy failed part way through with a cyclic redundancy check error. How can I get past this and back up my data?

A cyclic redundancy check, or “CRC” error, indicates a bad spot on your hard drive. That you see it when trying to copy a file means the bad spot may be within the file itself.

We need to verify that, try to recover your file, and repair your hard drive.

Then we need to learn from this.

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Dealing with a CRC error

Begin by trying to copy the file exhibiting the CRC error to another location. If it copies without error, then the CRC error was in the previous destination, not the original file. If the error remains, save a copy of the file, even with the error, and try to repair the disk using surface-scanning tools. Use CHKDSK or try to repair the file with file-specific data recovery and repair tools. Finally, consider whether you should replace the disk on which the error occurred.

What’s a CRC error?

Cyclic redundancy check, sometimes also called a checksum, is a fancy name for some complex math that detects when data has been damaged. It starts with a formula that takes the data in question, calculates a number, and then stores that number with the data. Later, the data can be read, the number calculated again, and if it matches the number stored originally, all is well. If the number calculates differently, then something’s wrong and you get a CRC error.

Let’s say our algorithm is to simply add up the numbers representing our data.

If our data is:

097 115 107 108 101 1111

We’d add those numbers, resulting in a check sum of 639, which is added to the data.

097 115 107 108 101 111 639

That data is written to disk. Later, the disk is damaged or writing to the disk itself had a problem, changing one of the numbers.

097 115 107 122 101 111 639

Now the math doesn’t add up. We know there’s a problem. That’s a CRC error.

In the file or not?

We’ll start by making sure the problem is with the file being copied, since it’s also possible the problem is with the hard disk location being copied to.

It’s a two-step process using Command Prompt.

  1. “CD” to the folder in which the file resides.
  2. Copy the file to NUL.

NUL is a special device file name meaning “nothing”. This operation copies the file to “nothing”. This is helpful because the only disk access will be to read the file; there’s no attempt to write to the disk.

First, locate the file. If you’re not sure where a PST file is, Where Is My Outlook “PST” File Located? has instructions to find it. As an example, my file is in “C:\Users\lnote\Documents\Outlook Files\Outlook.pst”.

Run Command Prompt, and enter the two commands corresponding to the two steps we listed above.

CD “C:\Users\lnote\Documents\Outlook Files\”

copy Outlook.pst NUL

(Replace my example location or file with yours, of course.)

If a copy to NUL works without reporting an error, the problem is likely not with the file but with the location you were trying to copy it to. My recommendation would be to copy the file to a different disk entirely — perhaps a USB stick, external drive, or something else.

If the copy to NUL fails with a CRC error, then we’ve confirmed that the bad sector on your hard disk is being used by some portion of the file. In that case, we have some things to try.

Try to fix the file

CRC ErrorIf the problem is in the file itself, we start by making as best a copy as we can. This preserves a copy in a state where “it can’t get any worse than this”. Some data within the file may be lost, but you’ll have copied as much as possible before taking any additional recovery steps.

Once again, we want to copy the file to a different disk, and once again, this is best done within Command Prompt.

CD “C:\Users\lnote\Documents\Outlook Files\”

xcopy /c Outlook.pst D:

(Replace my example location with yours, and the “D:” drive with the drive letter assigned to the drive to which you’re copying the file.)

Two important things to note: we’ve used the xcopy (for eXtended copy) command, and we’ve added the “/c” switch, which keeps copying even if it encounters errors. As you’ve already experienced, the default behavior of both COPY and XCOPY, as well as copying a file using Windows File Explorer, is to stop if an error occurs.

Now that we’ve got a “no worse than” backup copy, we can attempt to repair the disk.

Try to fix the disk: disk surface recovery tools

If you’re willing to spend money, there’s a possibility we can repair the hard drive.

Tools like SpinRite analyze your hard disk and repair sectors without modifying its contents. If SpinRite runs on your machine (sadly, it may not on more and more machines, as it’s not been updated in some time)2 and a bad sector can be recovered, it’s very possible that SpinRite, or other tools like it, will recover it.

Running tools like this is not without risk. If your disk is on the verge of failure, the work of analyzing and recovering the data could push it over the edge into a more catastrophic failure.

Try to fix the disk: CHKDSK

If surface analysis and repair tools don’t do it, then Windows’s CHKDSK utility is the next thing to try. It’s not as thorough, and it doesn’t perform the same deep analysis and recovery, but it can help the disk recover from some types of failures.

Once again, in the Command Prompt:


The “/R” parameter — for “repair” — directs CHKDSK to check for disk physical and surface errors and repair them as best it can.

If this is your system drive (most often C:), the command will not run immediately, but will be scheduled for the next reboot. You’ll need to reboot to make it happen.

After CHKDSK is done, try making another copy of the file. If it works, save that as a possibly fixed copy of your file.

Even if CHKDSK repairs the problem, I’m torn about how much you can trust the hard disk. You could still experience future failures. Given that disks are relatively inexpensive compared to data loss, I’d be tempted to replace the drive, especially if this is not the first instance of an error.

When all else fails

If none of the steps above repair the bad sector or otherwise recover your file, you’re a little screwed.

It’s now time to work with the best-effort file you saved earlier and, depending on what kind of file it is, try to recover the contents. In your example, an Outlook PST file, that means running scanpst on it, which will scan the contents of the file and attempt to recover what it can. There will most likely be data loss — sometimes a lot of data loss.

That’s why I encourage you to never run utilities like scanpst on your only copy of the file. You always want the original to go back to in case there’s something else in it you can recover manually.

For other types of files and applications, it depends entirely on how that application deals with a partially corrupt file and whether it can be repaired.

Do this

Which brings me to my last point.

If this is the only copy of the file — if you will suffer significant data loss if this file has been damaged — then you haven’t been backing up.

Start. Backing. Up. Now. This was a wake-up call. Even if you successfully recover your file, you should be scared.

Start backing up your important data. Now. In fact, start backing up everything, whether you think it’s important or not. The next time there’s a problem, you may not be as lucky.

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Footnotes & References

1: The string “askleo” in decimal ASCII. To be clear, actual CRC algorithms are significantly more complex and robust at detecting errors.

2: I’m still looking for a good alternative that would give us the same surface-repairing results.

80 comments on “How Do I Fix a CRC Error When I Try to Copy a File?”

  1. Hi Leo,

    First of all I just want to let you know how critical and helpful your site has been, particularly this page. Maybe you don’t think about it but you are really able to have a huge impact on people’s lives.

    For example, my boyfriend is a grad school student in the middle of an important project with a deadlne, and as is usually the case, his computer crashed at the worst possible time. I’m helping him by trying desperately to back up his data and save his hard disk because he can’t, and because I have a little more computer experience than he does; without having found your site on my computer we would not have known what the “cyclic redundancy” message we kept getting was. It is a good thing we ran the check disk command when we did because every time we started his computer, even in safe mode, more data was being lost to the point where we were almost unable to start it at all the last time. So without your help, we would have a huge loss on our hands, and being students we just don’t have the money to buy a new computer. I just wanted to say thank you very much for what you do! You are indeed a lifesaver- or at least a semester-saver!

    One question I have- Running the chkdsk command, literally hundreds of bad clusters are being repaired. After the scan is done running, will we be able to access any record or list of what has been repaired? There are simply too many to keep track of, and seemingly no way to save.

    Thanks again, Leo!

    Hash: SHA1

    Not that I’m aware of. I’d recommend backing up and copying off as much
    of that hard drive as possible, and replacing it.

    Alternately, you might try getting and running spinrite – it may be able
    to recover/repair the drive.

    Version: GnuPG v1.4.6 (MingW32)


  3. Hey Leo,

    First off I want to thank you for your site. It’s incredibly helpful when things like DELL Help Center fail to come through.

    But I do have a problem. I know the above article deals with copying a file, but my problem is deleting a file. I first got the cyclic redundancy check error message when I tried to empty my Recycle Bin. A window popped up stating the following:

    Cannot delete Dc224: Data Error (cyclic redundancy check)

    Well, I’m sure its a particular file that’s the problem, because I can go into the Recycle Bin and manually delete everything. But even if I delete all the files shown, the recycle bin still reports the presence of one file. I believe that one of the files I tried to delete did not do so completely. But I’m not sure. I’m not sure where to go from here. Should I even keep deleting the files in the Recycle Bin one by one?

    Up till now, my computer hasn’t had any problems and now this. It’s always something.

    Even if you don’t reply, your article was incredibly helpful in informing me of this type of error. Thanks for your time.

    Hash: SHA1

    It sounds like the CRC error is in the filesystem itself, not one of your
    files. This is actually more dangerous because if the filesystem itself becomes
    corrupt you could loose multiple files.

    I’d strongly recommend the SpinRite, or at least the CHKDSK options noted in
    the article.

    Version: GnuPG v1.4.6 (MingW32)


  5. Hi Leo,

    I also got a “cyclic redundancy check error” when trying to copy my Outlook.pst file. Interestingly, I never got any crc errors with any other file on this harddisk and I don’t even use Outlook very much (hardly at all in fact).

    What’s more, I found your webpage because I googled for “hard disk error bad sector cyclical redundancy”, so I wasn’t even looking for Outlook related information.

    All this makes me suspect that Outlook somehow “creates” these errors. (CHKDSK didn’t report any bad sectors anyway).

    Hope this info is useful somehow.

  6. Correction regarding my own previous post:
    In fact there actually was a bad sector, when I did a real CHKDSK (from the command line), and some of my Outlook data was lost.

  7. Hello My name is Salman from Afghanistan.I have some sound files in a CD. There are about 70 .RM files on a CD all of them are fine but when I want to copy some of them there is this error.
    I read the above instruction. but I want to ask you that is there a software to fix it? is there a good way to solve it?
    because I need my files please tell me about it as sson as possible.the file itself is fine it works and can be read. but when I want to copy there is this error Data Error (Cyclic Redudancy Check) What should I do with this error? Thank you very much

    Hash: SHA1

    If you’re positive that the files can all be played completely, then they can
    be read, and I would assume that the CRC error is happening on the device
    you’re writing too. Try copying them to a different drive or device.


    Version: GnuPG v1.4.7 (MingW32)


    Hash: SHA1

    Folks, PLEASE read the article. The whole article. It’s pretty clear:

    “If this copy fails, then we’ve confirmed that the bad sector on your hard
    disk is actually being used by some portion of your file.”

    You have a bad sector on your hard disk.

    Again, as the article outlines: chkdsk may help, spinrite stands a very good
    chance of helping.

    But some CRC errors cannot be corrected. Again quoting the article:

    “At this point, if none of the steps above have repaired the bad sector or
    otherwise recovered your file, you’re just a little bit screwed.”

    I hate to see everyone waiting for a response from me, when my answers to your
    questions are already in the very article you’re commenting on.

    PLEASE read the article.


    Version: GnuPG v1.4.7 (MingW32)


  10. Hi Leo,

    All I can say is THANKS for introducing me to Spinrite…had a little trouble with my bios at first, but the tech support got right back to me with the solution and now I have fully recovered my 1.7GB PST file.

    I HIGHLY recommend Spinrite to anyone having problems with their HD.

    Thanks again,


  11. I tryin to copy avi files from a dvd . The files Seem so play usin media player or win amp but gets stuck at certain point . . Some copy and play perfectly others say cyclic refuncy check . . How can i copy these files which play but dont copy . . I tried to copy it to another removal disc so its not my hard drive that has a problem . .Wat do i do

  12. Several people have noted that XCOPY does not, in fact copy files with CRC errors, to which Leo responded

    “Folks, PLEASE read the article. The whole article. It’s pretty clear:

    If this copy fails, then we’ve confirmed that the bad sector on your hard
    disk is actually being used by some portion of your file.”

    Leo, PLEASE read your own article, to wit, the context of the sentence you took out of context was when copying to NUL, not when using XCOPY:

    C:wherever>copy Outlook.pst NUL
    1 file(s) copied.

    This reads the entire file by copying it “nowhere”. If this succeeds the problem is not actually with the file itself, but the location you were trying to copy it to. My recommendation would be to copy it to a different disk entirely, or a different machine on your local network.

    If this copy fails, then we’ve confirmed that the bad sector on your hard disk is actually being used by some portion of your file.”


    “Two important things to note here: we’ve used the xcopy (for eXtended copy) command, and we’ve added the “/C” switch which keeps copying even if errors are encountered. As you’ve already experienced, the default behavior of both COPY and XCOPY is to stop if an error occurs.

    Now that we’ve got a “no worse than” backup copy, we can start attempting to repair the disk. “

    All of this was a discussion of recovering a single file. You failed to recognize that XCOPY skips a file with a CRC error and keeps copying OTHER files, rather than stopping altogether. This is irrelevant when attempting to recover a single file.

  13. Just quick message to Rob, I would start to break out that PST into several, perhaps by year. In my former life as an admin, I know that when you start to approach 2gb size in PST files they tend to corrupt very easily.
    I used to break out users’ PST files by 2002, 2003, 2004, etc, leaving the last two years or so in the current PST file.

    Also, thanks for the article, it was helpful

  14. I purchased a program that has an application CD and an application update CD. Then there are 6 CD’s that install the data. Mostly .cab files that contain large single files that are spanned. When I get to the 5th CD, there are two cab files. one contains the remainder of the 4th CD spanned cab file and the beginning of another cab file that spans to the 6th CD. When installing, the 5th CD stalls just before the end of the cab that flows into the 6th CD, but then it pops up a window that says installation complete. it doesn’t ask for the final disk and I can not access any of the data or the program at all. If I try to copy the cab or extract the file it contains, I get Cyclic redundancy error. If I copy it from cmd prompt with a c switch, it still errors CRC because it’s all one big file. I tried an error fixing program that got through the file transfer to HD, and I burned it to a new disk, but it still is premature installation and won’t work. The file in the cab is called rfile002.001 and spans (disk5) and (disk 6). any ideas? I know it is the 5th disk and not my drive.

  15. Dear Leo,
    I am out of ideas!

    I have 1 disk 2 partitions. Back-up C: to D: with Ghost works fine. Have done it multiple times. Also Wondows / properties / Chkdsk does not find a problem. This would indicate no problem with the hard drive.

    But – back-up to DVD, I get a CRC error on the last DVD consistently on both DVD-R & DVD-RWs for either partition. Got a new DVD, still get the error.


  16. Thanks for the tips! My users OST file was corrupted and I could not copy it to “null”. Since we are lucky enough that we keep it on the server, I was able to delete his ost file and it re-created itself when I reopened Outlook.

  17. Hello leo.
    I’m trying to reinsall win-xp-pro,but i keep getting this error,(data error cyclic redundancy,one of the components that windows need could not be installed).How can this problem be fixed? And how can i fix this problem if there’s no operating system on my (ACER ASPIRE/5050 LABTOP)? Because i’m stuck,it started 1/2way and stopped,so now i’m stuck with no os. please help me.Oh,and also i tryed to use my recovery disc,and it went 1/2way and an error poped up please help me.

  18. At times a file or software being downloaded from the internet may get corrupted . The corrupted file or software will not work and will give the cyclic redundancy check data error when one tries to delete it from the hard disk. Running CHKDSK can help in deleting the file or software completely.

  19. I have bought a WD passport essential (250 GB) external hard disk! There were some setup files (included software with synchronization and recovery)….even I didn’t removed or replaced these files in WD, I tried to copy and nothing (cyclic redundancy and some I/O errors-even the usb ports are well installed -no driver problems)…then I have formatted it, and still the same problem …Also, I read and proved your advices, and still :( nothing…Please help me, because I spend a lot of money for this device and I cannot use it…..

  20. Hi I have problem in My HDD for PST file where Bad sector is causing to read pst file. I am unable to transfer to another HDD or can not take backup for PST. I tried CHKDSK /R and SANPST but did not help. how can I fix this without buying SPINRITE, PST file is about 1.9 MB, please help me I am stuck using outlook for 3 weeks.

    SpinRite remains my next recommended step. Yes, it may not work (you can get your money back, I believe), but I know of no other tool that does what it does as well as it does it.


  21. Hi, I was having trouble getting a file from a cd because I kept getting this CRC warning so I download a program called CDcheck which works wonders…

    It continues to copy the file even after the CRC warning and it also works by copying from one destination to another on hard drives or folder to folder. It also gives you a detailed report of how many errors you recieved so that you can, for example, clean the cd and see if you get less errors which would mean more data would be recovered. Very usefull program I do recommend.

  22. Leo, thanks for your help on this. I tried all of the above when my Outlook began having problems. It didn’t work. Amazingly, I did the following:

    1. Did a simple Disk Cleanup.
    2. Used a utility to clean up the registry.
    3. Believe it or not, DEFRAGED the harddrive.

    Outlook is as good as new. It must have moved the file off of the bad areas. I did a diskcheck and yes, I had a bad areas. So now it’s going to be, clean up the harddrive and get ready for a replacement, just to be safe.

    I just wanted to pass this along.


  23. Hello leo.
    I’m trying to reinsall win-xp-pro,but i keep getting this error,(data error cyclic redundancy,one of the components that windows need could not be installed).How can this problem be fixed? And how can i fix this problem if there’s no operating system on my (Desktop PC? Because i’m stuck,it started 1/2way and stopped,so now i’m stuck with no os. please help me.Oh,and also i tryed to use my recovery disc,and it went 1/2way and an error popped up again please help me.

  24. Leo, Can you please tell the best way to clean up the registry. above Ed mentioned that he cleaned up the registry with some tool, can you please share the name. My laptop was working fine but now its extrmely slow. Yes I installed and uninstalled lot of applications, lot of them just downloaded as free software from net.

    Please help.

    Try this article: What’s the best registry cleaner?

    – Leo
  25. I tried the xcopy but it gave an “Access denied” message. Also if I try the chkdsk first, and if that doesn’t recover everything, can II still use spinrite later or will I have changed the structure of the file and therefore loose any chance to recover the rest?

  26. I tried to do the procedure using the dos prompt to xcopy /c my archive.pst file that had been giving me crc errors. the xcopy /c command resulted in 0 files copied, crc. Any thing else I can try to recover this archive.pst? Thanks.

    In your shoes, I’d try SpinRite. It’s not free, but it could allow you to recover the file(s) on your disk in a situation like this.

    – Leo
  27. my system saying eror and to run chaeck disk
    but when i run chkdsk on windows and ms dos it says it will be done at system restart but it not don what to do
    pls can any body help me
    [personal email address removed]

  28. Hi again…A follow up to my post of October 8.

    That fix didn’t work long term, the Outlook.pst because corrupt again.

    I believe I have a real fix for the Outlook issue. After going after many of the solutions xcopy etc, I decided to try something very basic. I exported each section of Outlook ie Calendar, Contacts…etc…etc. to a seperate file outlook calendar.pst etc on a seperate hard drive. I had 2 HD’s in the system and plan to trash the bad one, only using the 2nd HD in the system once it’s reformatted. I copied each folder seperately. To test it, I imported each of the pieces to the Outlook Archive file and it worked perfectly, all of the information is in tact.

    One other interesting note, for those that mentioned their Outlook.pst is over 1 gig, my corupt file is 1.19 gig, the archive.pst file is only 128 meg. I guess Outlook does a great job wasting space.

    I am going to move both the seperate files and the archive.pst to the new Outlook once the machine is totally refreshed.

    Good luck.


  29. LEO, I’m having huge problems with this CRC error. I can’t install corel draw which i really need right now, and i’m installing it from free downloaded trial version from OHP of Corel. I’m having the same error, when i try to check my large format photos in a folder. My laptop just stops for a while.
    And when i download some files and try to extract them using WINRAR, i get the same problem.
    I’ve done the register cleaning, scanned with antivirus programmes.
    I repaired my Windows XP for the 5th time now.

  30. Leo, thanks a million!

    XCOPY /c failed three times. I then used the XCOPY with /cf attributes and that worked!

    I was able to copy and read the corrupted excel file!

    Thanks Again,

    Sales at

  31. When I tried “C:>CHKDSK /R”
    The console said:
    “The type of the file system is NTFS.
    Cannot lock current drive.”
    What should I do?

    It should also have asked if you want to schedule the chkdsk for the next time the system is rebooted. Say yes.

    – Leo

  32. hello everyone….i believe i have had this CRC error long time ago…the problem may look little but can be very effective since using variable registry softwares and change of directory doesnt actually solve the problem….the first time i had this problem i tried every possible way to fix the problem…but later on i found the only issue tht has brought to this problem is the RAM itself….sometimes the RAM may work well but not necessarily the RAM is working well for installing softwares or games….i suggest tht a RAM checkup is necessary orelse the only other issue can be coz of the Motherboard…

  33. Hello Leo I have a very basic question. I am trying to follow the instructions; however, I do not know what exactly to type into the first command prompt to tell it where to find the file. What is correct format I know the path C:Documents and SettingsKevinLocal SettingsApplication DataMicrosoftOutlook but any time I type any variation of this it tells me “whatItype” is not recognized as an internal or external command. I am using Windows XP…

    Much thanks !

  34. Just wondering Leo, don’t you think it is more advisable to just replace the drive, is total failure not eminant.? when it starts to spit out crc errors. My neighbor brought me a laptop that would not boot, I installed a new operating system onit and it was fine untill I started installing programs and got crc errors. Check disk reveiled a bad block chkdsk /r found dozens of orphaned files,is this not the pretence of doom for this drive? And lastly what article at the top of this page are you refering to that I should read or this post will be ignored, I clicked on “Read the article at the top of this Page” but fail to see the relevance, with all due respect. I gave them a two year old drive from one of my machines and in 3 weeks it failed on them. They must have dropped it or the dog knocked it off the table, so why not tell people that it could be the end of the line for their drive and casper it to a new drive and remain worry free for a few years.

    The article at the top of the page is the article you’re commenting on. People regularly post comments when it’s clear that they haven’t even bothered to read the article, hence my admonition that they do so.

    As for advising them to discard a drive – it’s a tough call. The fact is that a “rash of CRC errors” need not mean that the drive is about to fail completely. It could, of course, but it’s also not guaranteed. Very often running a tool like SpinRite will both recover the data (something giving up will not do), and refresh the media such that the bad areas are either repaired (magnetic errors) or avoided (physical errors). Data recovery is, after all, an important consideration. With drives being as cheap as they are these days, it’s hard not to argue for replacement if recovery isn’t an issue, but even then it’s not always a simple call.


  35. hi everybody

    i just had a failure of my portable hard disk drive. It gives me CRC notification.
    When i connect to laptop, system cannot read it.

    How do i solve this?
    Please help me, teach me step by step.
    I have very important files in it.

  36. Hey i just had the problem. I was trying to burn a disk from my laptop while laying on the bed. Because i the laptop was slightly tilted i think it came up with the error but when i put it on a flat surface it worked.

  37. Kevin wrote, September 17, 2009 11:38 PM

    “What is correct format? I know the path C:Documents and SettingsKevinLocal SettingsApplication DataMicrosoftOutlook but any time I type any variation of this it tells me “whatItype” is not recognized as an internal or external command.”

    He received no response.

    Here it is !

    He should type (after the “C:>”) :-

    C:> CD “C:Documents and SettingsKevinLocal SettingsApplication DataMicrosoftOutlook”

    DOS screeches to a halt at the first space (between “Documents” and “and”), so you have to enclose the path by quotation marks, as above.

    But YOU knew that ;-)

  38. CRC errors are generated because there are some bad sectors in the hard disk. These bad sectors might have damaged the PST file that you are trying to copy and hence the CRC error is generated. In order words, the PST file that you want to copy is damaged and corrupted.

    Go to C Drive> Program Files> Microsoft Office> Office 2007. After doing this you will see the PST files. Right click on it and go to the Properties and then select the Compatibility tab. Click on it to clear down all the Compatibility Mode Check Box. After doing so, click on Apply and then press OK. Restart the computer and your problem is sorted out.

    If still the problem persists, then opt for any 3rd party Outlook PST Repair software to get rid of the CRC errors in Outlook and repair the damaged PST files.

  39. Hi Leo,

    I’ve been trying to fix cyclic redundancy error in Outlook for a good two or three days. We have Outlook 2000, and resolving this is proving to be incredibly difficult. We’re trying to get away from paying by the hour on the phone with Microsoft, ‘Outlook PST Repair’ seems innocent and truly there in the spirit of helping, but choosing files??? huh????? Baffling. Our cable service provider used to IT support of 2000 in the old days, but they don’t anymore.

    My question, as the problem’s probably hopeless, is can we download latest ver of Outlook X and retrieve all the old stuff AND keep our old email addresses? From what I read, the ‘cyclic redundancy check’ is a ‘game over’ thing. If you could be so kind as to advise, I’d really appreciate it. Life without email doesn’t feel very good.
    thanks, and Happy New Year

    CRC errors have nothing to do with your email address, they are simply a problem with a file on your hard disk. In this case the file is your Outlook PST file. I’d have you follow the suggestions outlined in this article. There’s nothing that would cause you to lose your email address.


  40. First copying the file normally to any location through copy-dialog in windows explorer was impopssible due to CRC fail.

    than copying through cmd.exe to location “nul” went nice, then the extended /C copy failed due to CRC fail…. Why fail?? Why stop due to CRC when /C-copying? I’m sad now.

    Here is cmd-text:

    C:Documents and SettingsKikki.KIKKIS.000My DocumentsAzureus DownloadsEl Lab
    erinto Del Fauno[DVDRip][Spanish][]>copy *[].avi
    El Laberinto Del Fauno [DVDRip][Spanish][].avi
    1 file(s) copied.

    C:Documents and SettingsKikki.KIKKIS.000My DocumentsAzureus DownloadsEl Lab
    erinto Del Fauno[DVDRip][Spanish][]>xcopy /C *Rip][Spanish][www.].avi E:Peliculas
    C:El Laberinto Del Fauno [DVDRip][Spanish][].avi
    File creation error – Data error (cyclic redundancy check).

    0 File(s) copied

    C:Documents and SettingsKikki.KIKKIS.000My DocumentsAzureus DownloadsEl Lab
    erinto Del Fauno[DVDRip][Spanish][]>

  41. I tried the copy to NUL and confirmed the error is with the file. HOWEVER, I tried the 2nd step of xcopy /c and that, too, failed with the same CRC error. I was hopeful but it came back as 0 files copied.
    Now what? Or is the next step to try and repair through something like SpinRite or Outlook PST Repair? I need to fix this so I can transfer it to my new laptop. Is there a risk in trying to fix it that I will render it unusable?

  42. Numerous people have commented that “XCOPY /C” does not work when attempting to copy a single file from a corrupted media. I haven’t been able to test for magnetic drive corruption, but I can state with certainty that “XCOPY /C” does not allow me to retrieve a CRC-damaged file from a CD/DVD. I suspect the same is also true with magnetic drives; “XCOPY /C” only skips files with errors–it does not skip errors in files.

    Another post here suggested using CDCheck: . This worked well for me to recover a file from a partially corrupted disc. Sadly, I didn’t make enough PAR2 files to completely restore the file. To add to Leo’s reminder to backup, I want to also remind everyone (especially backup software developers) that backups are often useless without some sort of built-in redundancy. Media will, eventually, corrupt. Thus far manually creating PAR2 files has been my only option. (WinRAR also offers recovery volumes, but that of course requires archiving the files–PAR2 does not require that.)

    I’d love to see more backup software (esp. partition software) include the ability to spread archives over multiple files and include redundancy/repair files automatically, based on user settings.

    Good luck to everyone recovering his/her files.

  43. Hi all,
    I had a CRC error in some DVDs recorded by my cancorder (Samsung) I would like to create some copies for my friends but I got the CRC error. I tried xcopy and I could copy all files from those DVDs to my HD then I used Nero to create DVD copies.
    Thanks for that tip.

  44. Bad sectors were causing crc errors in avi and mkv. 3 gb, so was unwilling to redownload. Found this page and xcopy failed. After Wading through countless data recovery options on goggle found jfilerecovery. Portable, did not install just ran. Copied files to another partition. Reported read errors but did not freeze or hang. Copied files play without recoding although with minor glitches where data was lost.
    Fast, precise and completely free. Its a java executable .jar so must have sun microsystems jre installed(15mb download, free).
    If anyone else ends up here like me then would recommend this before trying/buying any recovery app.
    Thank you.

  45. jfilerecovery recommended by anon worke fine here. i had to recover a pretty important videofile which worked out find. after a few retrys with smaller blocks the effective amount of data missing shrinked fom 1,3mb to 97kb in my 1,57gb file. great!

  46. I read recently on the net that rubbing a banana on your unplayable, scratched DVD fixes it. Yeah, right. But here is what I did for my Cyclic Redundancy Check error on my very scratched CD. I actually rubbed my foot on it as I remember. I used Turtle wax. Unbelievable!!! Do you know how many years I tried to get this CD to copy back to my puter? this is how I did it. I dipped my index in the Turtle Wax bottle, softly rubbed it around under it, and softly “played” the CD on a clean, soft towel until it shined. And shine it did. I had nothing to loose.

  47. Leo – THANKS so much, your info here was very useful! i am so so glad that i copied the data off the drive as quickly as i did (due to your suggestions)… the drive died totally just before it copied the very last few files off (so i only lost maybe 5% of my files, if that). if i had waited, well… it could have been total disaster.

    some other handy options for xcopy, that i found useful in this context:

    /E – copy all subfolders too, recursively (and create new folders in the target, even if they are empty)

    /I – indicates that the destination (if not definitive) is a (new) folder, not a file.

    /H – copy hidden/system files too

    so… i guess my next step is to try Spinrite. wish me luck!

    cheers and THANKS
    Peter “Fish” Fisera

  48. I was getting a device i/o error and also sometimes a Data Error (Cyclic Redundancy Check) error when I tried to move or copy certain files from a Maxtor One Touch external hard drive. I did this below and all the error messages stopped and I could move and copy all the files that caused these errors: (WIN XP)
    chkdsk e: /r
    (e=Maxtor one touch drive).
    try it!

  49. Had exactly the same situation as your example, copying an outlook.pst file. This didn’t work. This time I get “File creation error – Data error (cyclic redundancy check)

  50. Leo,

    I am using you method to recover some of the bad files on my hard disk. I was snake bitten, my hard drive failed, with numerous CRC errors on pst files (40 and counting). Very time consuming. Went to use my External HDD backup and I dropped it and now the drive us unreadable. Any thoughts on this? I need major help.

    I’d fire up SpinRite on the original drive.


  51. when i try to copy contents of a DVD, cyclic redundancy check error appears. I just got a new hard drive. And I am no good at this stuff. Please help

    If you’re copying a file from CD or DVD then more commonly that’s where the problem is – the CD or DVD. Try reading it on a different machine.


  52. CHKDSK /R worked fine for me. The icon for the faulty drive D was showing but I couldn’t access any of the data and the drive wouldn’t boot up. I started by installing a 2nd copy of xp on a separate drive and setting it as the boot drive in BIOS. This became C and the faulty one D. By using c:/chkdsk/r d: the 5 stage checking process began and after it finished I was able to read and access all the data and, most importantly, copy all relevant data onto C. When I’m finished with it drive D will be dumped!

  53. I have a hard drive with many bad sectors. I was not able to salvage many documents and photos off of it because of CRC errors. Chkdsk/r found and tried to repair files, but many were still not able to be copied to my new hard drive. Following your advice, I began to use SpinRite, which does seem to be an excellent tool for bit-by-bit data correction, but I realised this was impractical after an hour of correction and calculating that it would take about 200 days to correct the 80 GB drive.

    Looking for a better solution, I found Roadil’s Unstoppable Copier. This let me target only the files I needed and the files appear copied and readable (as best I can tell, uncorrupted). Even on files that it reported read errors, the new copy opens correctly and I do not see any errors. This all just occurred so there may be problems I don’t know about, but I seriously think you should mention this product on your CRC Error page. By the way, for me at least, XCOPY /c/s stopped itself after a few errors. Apparently the /c does not keep overriding after a few error messages (more than one, less than ten).

    All things to consider mentioning in your article. Thank you anyway, despite the limits of your advice.

    Michael Leslie

  54. Hi Leo – great article. Mine is .pst file. I’ve tried the xcopy /C you suggest to an external drive and I get a ‘File create error: data error (cyclic redundancy check)’.
    Any thoughts?

  55. SpinRite won’t work if the hard drive of the machine you are using is SATA and cannot be switched to compatibility mode. ASUS notebooks are an example of a machine it won’t work on.

  56. Jayron, to open the command prompt in Windows 7 all you need to do is press the Windows button in the bottom left of your screen, then simply type “cmd” without the quotes.

    If this doesn’t work hold the windows/start button on your keyboard and press the letter “R”. This will open a Run window.

    Type “cmd” in the Run window and press “Ok”. That should bring up your command window.

  57. Thank You!!!! 3 months since I got a new computer and have lived without a third of my old data. Photos, paid for music and video. 4 hours on and I am still transferring to an external hard drive! just thrilled that I haven’t lost my precious memories. Used CHKDSK coz didnt have the funds for spinrite, and so far so very very good! I love technology but not computer savy per say, this was the 1st solution I could follow and obviously it has worked. Thanks again

  58. xcopy /c did not work.
    I used jzip to zip all the files in the dir, then copied the zipped file to destination.
    If only one file in a directory, make some text files, and then zip all and do the copy. Then later just delete those worthless text files.

  59. I use a borrowed computer and burn data DVD’s to archive mixed media. I used to use “Nero” software on a Windows XP PC,but the owner did away with that,and re-formatted his machines.

    So now,a data DVD made months ago will no longer work because of said “cyclic error”. I must retrieve this data if possible (the original flash drive it was on,was stolen.)

    Nowadays I use “NCH” softsare…Excellent,but I just didn’t have access to their Express Burner back then. (So would getting access to another
    “Nero” Start Smart site fix the problem?)

    The data files jusst won’t copy onto a new disc.
    Only a couple of files will play.

  60. Thanks a lot for the above solution.
    The Xcopy /c command worked like a charm!! It saved my 8 GB PST file which was stored in a bad sector location of the HDD. Using the above command I was able to copy the file to a working hard drive successfully. You are a life saver, Leo!!

  61. Tried the “chkdsk /f” and “diskpart” commands that I saw on microsoft webpage many times, they seem to work a bit coz I now can open the folders i couldn’t open, HOWEVER, i tried copying now, but still freezes the computer in other cases giving the cyclic redundancy error… I’m stuck, I don’t know what to do… It’s an LG 2TB external hard drive and I don’t want to lose information, please help!!!

  62. ive got a problem, my external hd is 1.5TB full of data, and internal is 60GB, cant back it up, what do you suggest? could this cause windows to freeze or lock up every now and then?

    If by “can’t back it up” you mean you’re getting a CRC error that prevents the backup from completing, then you need to follow the advice in the article you just commented on. Yes, in a worst case scenario a CRC error can cause system slowdowns, crashes and hangs.

  63. ok, ive managed to find a single folder that if i click open, i get the crc error, and then it asks me to format the external.
    would deleting this folder solve the problem, booting from linux? and is it possible to solve this error without any data lose?
    thanks Duncan

  64. So often the people writing articles like this are clueless and do more harm than good. Fortunately this guy is good! And I agree with him about Spinrite. It is close to magic. Back when 40 MB drives cost more than computers do now I used it on every system I put together.

  65. For me, the xcopy failed with error “File creation error – Data error (cyclic redundancy check). ” . Then I tried chkdsk like you suggested. Chkdsk seems to go into an infinite loop. In the first pass, it completes the 5 stages of DASD cehcks. It also fixes two files with messages like “windows replaced bad clusters in file 28294 of name “. Then it reboots and windows XP gets to chkdsk again. I can barely see messages like volume is clean and Windows has just finished chkdsk. And there comes the BSOD (blue screen of death). This cycle has repeated at least thrice with exactly the same results each time. I guess this is some iNifinte chkdsk loop. The BSOD by the way is about SESSION5_INITIALIZATION_FAILED.

    does it mean I should not hope to recover this file I have? Or the only hope is to go for some kind of commercial recovery softwares?

    This actually sounds like a job for SpinRite. I believe they’ll refund your money if it doesn’t fix the disk. (And if it does, I’d replace the drive anyway.)

  66. Leo A. Notenboom,

    This is Chandrasekar, even for me also I have faced this problem that if I have copy the Outlook pst data file to any other location while copying process at the end of the stage it will say that ” Data redundancy check error”

    I have done all excerise that chkdsk /r /f & scandisk ( virus scan) and scan the PST recovery tools, XCOPY , Copy.there is no possible results,

    Simple way but we have to check,

    Finally, I used to recovered the NTBACKUP tool to backup the PST files, restore in another disk. Work was done not this was resolved my issue& It Works.

    J Chandrasekar.

  67. Dear Leo,

    Thank you very much Leo for your advice on spinrite.
    When I read your suggestions I decided to buy my own copy. I have run spinrite, first at recovery level and later again level 5.
    spinrite fixed all the bad spots and even succeeded in recovering 25 lost files. Just one file was left unrecovered. Lucky for me it was not an important file. I am vigourous in making online and offline backups with acronis, which was how I discovered that bad spots were starting to arise. I will follow spinrites advice to regularly run it in order to prevent near future bad spots occuring, or if they do, to be in time to mark them as unusable.
    Thanks again; $89 well spent.


  68. I tried running spinrite but it will not recognize any drive as being a removable drive. It will not install, what is the problem.

  69. My external hard disk has the CRC error. I took your advice and run the chkdsk and fix it. It works. I can access my external hard disk now.
    Thanks Leo :)

  70. Roadil’s Unstoppable Copier works like a charm. wish i could show you a screenshot. and its free. recovered file that displayed crc error in command line with 94.8% integrity! thanks mike!

  71. over my years in computer & network (well i wouldn’t say network at this point cuz i can only fix what’s happening on the clientside) repairs this is the first kind of problem that i’ve encountered, February 2016, mark the spot. that me & a bunch of other network technicians in, can’t figure out. (checked the whole internet for anyone who had pin-point the problem, no luck.). I suspect modem or the ISP side at this point. planning to call on their technician to either check the physical connections or force them to download something at my end that is not corrupt.

    my problem is the CRC failure only happen to huge files. 1GB – 2GB. it turns the text files in those big files into gibberish which shows corruption of course. i did checked my RAM, hard disks, spyware, viruses, defragmentation, drivers update, safe mode, unsafe mode, everything pass. rolled back drivers on the network card & nothing wrong with that. then check the modem for packet loss, some ping tests, called the ISP if there’s problem on their side. again. nothing. its like im on weed or something. problem is there but at the same time problem isn’t there. heck i even thought windows update causes it and started to uninstall all the window update i downloaded this year. and surprise surprise, nothing came up. diagnose shows that all of my network and laptop is running smooth as a baby butt.

    so my final attempt to diagnose this, is to borrow someone else working laptop and try to download from their’s, if it comes out okay then BAM. my laptop’s faulty. but if its CORRUPTED. i will buy weeds and smoke it. before i drag the ISP technician ass here and not make him leave until he fixes it.

    • Depends on what you mean by “initialized”. Run CHKDSK if you can. If the disk has no data on it, then I’d use Disk Management to reformat it (and NOT select a “quick” format).

  72. Hi Leo,

    I got a large VMware virtual disk file that have problem to be read from. I google the error and got here. This article brings me hope. But it seems quite old (before 2007 based on the comments history). I wondering if the information in the article is still realistic for 2019?



  73. Extremely well written. Just what I was l looking for, also I would add you can directly copy files with CRC errors using Gs Richcopy 360 or Goodsync , it is easy


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