The cyclic redundancy check, or “CRC” error, indicates a bad spot on your hard drive. The fact that you’re seeing it when you try to copy a file indicates that the bad spot may be within the file itself.
We need to verify that and then try to recover your file and repair your hard drive.
Then we need to learn from this event.
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In the file or not?
First, let’s make sure that the problem is actually with the file you’re copying since it’s also possible that the problem is with the hard disk location you’re copying too.
You’ll first need to locate the file. If you’re not sure, right click on the PST in Outlook, click on Data File Properties… and then the Advanced… button.
In the example above my file is at “C:\Users\lnote\Documents\Outlook Files\Outlook.pst”.
The next step is most easily done in Command Prompt. Run it, and then enter:
CD “C:\Users\lnote\Documents\Outlook Files\”
copy Outlook.pst NUL
(Replace my example location with yours, of course.) If you’re experiencing a problem with another file of some sort you would “CD” to the folder in which it resides, and then copy the file to NUL.
NUL is a special device file name that indicates “nothing”, and this operation copies the file to “nothing”. This is helpful because we know that the only disk access associated with this copy is to read the file; there’s no attempt to write to the disk.
If this copy to NUL succeeds, the problem is not actually with the file itself, but probably the location you were trying to copy it to. My recommendation would be to copy it to a different disk entirely, perhaps getting a USB stick or something else if neccessary.
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.
Trying to fix the file
Once we’ve confirmed that the problem is in fact in the file itself, we need to make as best a copy of it as we can, somewhere else. This sets a position of “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 some 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 other 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 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.
Trying to fix the disk: SpinRite
If you’re willing to spend $89 (as I write this) then there’s a possibility we can repair the hard drive. (At last report they do offer a money-back guarantee if SpinRite doesn’t work for you.)
SpinRite is a hard drive recovery and maintenance program. When you run it, it will perform a lengthy and exhaustive analysis of your hard disk 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) and a bad sector can be recovered, it’s very possible that SpinRite will recover it.
Even if SpinRite is unable to recover some of the data I would reboot into Windows and try to make another copy of the file. It’s possible that it was able to repair sectors causing the problem with the file you’re trying to access even if it reported problems elsewhere. I would not overwrite our first “no worse than” copy, but I would save this new file as a kind of “possibly better” copy.
Trying to fix the disk: CHKDSK
If SpinRite doesn’t do it then Window’s own CHKDSK utility is the next best thing. It’s not as thorough, and it doesn’t perform the same deep analysis and recovery as SpinRite, but it can, in fact, recover from some types of hard disk failures.
Once again, in the Command Prompt:
The “/R” parameter indicates that CHKDSK should check for errors and repair them as best it can.
If this is your system drive (most often C:), this command will not actually run the operation immediately, but will schedule it for the next reboot. You’ll need to reboot to actually make it happen.
After it’s done, try making another copy of the file. If it doesn’t work, then obviously CHKDSK wasn’t able to repair the error you’re experiencing. If it does, however, save that copy as a possibly fixed copy of your file.
Even if CHKDSK does repair the problem, I’m actually torn on how much to continue to trust the hard disk. You could still experience future failures.
If all fails
If none of the steps above have repaired the bad sector or otherwise recovered your file, you’re just a little bit screwed.
It’s now time to work with the best-effort file that 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 most likely will 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 that you can recover manually.
For other types of files and applications, it’ll depend entirely on the specifics of that application as to how it will deal with a partially corrupt file, and whether or not it can be repaired.
The lesson to learn
And that brings me to my last point.
If this was your only copy of the file – if you would have suffered significant data loss had this file become corrupt – you haven’t been backing up.
This was a wake-up call. Even if we successfully recovered your file, you should be very scared.
Start backing up your important data. Now.
The next time there’s a problem, you may not be as lucky.