# External harddrive - Data Error - Cyclic Redundancy Check



## computerclaudia (May 23, 2011)

Hi, 

Please could I ask for some advice. 
I have an external hard drive which from time to time told me that I couldn't access it without formatting it. Unplugging the USB and plugging it back in solved it. 

In My Computer it just shows as "H", not the name of the harddrive (Freecom) and when I click on it, it gives a Data Error - cyclic redundancy check. I have a back-up of 3/4s of the data but as always, need the other quarter desperately! 

You can feel that the drive is on, but I just can't access it. 

Have read through many posts and there seem to be quite a few programs that I can download but not entirely sure which route to take as I'm worried I might be doing more damage. 

Could anyone help me out? 

Thanks a lot in advance for your advice!


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## raptor_pa (Dec 5, 2008)

The CRC quite often indicates a physical failure. Is the drive identified correctly by cpacity in disk management?


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## computerclaudia (May 23, 2011)

Thanks Raptor-PA! If I go to device manager, the hard disk shows up. When I click on properties, it says that it's working properly. However, it stills says that I need to format the disk first and when I click NO, I get the CRC message. 

Do you have any suggestions? 

thanks a lot!


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## raptor_pa (Dec 5, 2008)

Disk management not device - right click my computer -> manage -> disk management


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## spaciousmind (Jul 8, 2011)

This exact same thing happened to me thismorning.... on an external WD usb connected drive.

Went into disk management and the drive file format says RAW..... its still showing 1.3TB full which is the capacity it would have been anyway.

can't access it with windows, get the CRC error thing. Havn't tried the format because I would really like to recover the data.
Havn't tried all the other options cause I wasnt sure which one applied to me.

I did get WD disk lifeguard tool to run some tests on it, upon opening the smart tests all said it was OK and healthy (although this didnt list any file system for it)
I got an error when tried to run the quick test so I am now doing the extended test....40 minutes in and everything is OK so far.

Im wondering if I should try and use this tool to repair the disk when it hits an error (it says use it with caution)...... Is there another option I should try first thats safer maybe?:4-dontkno
and If i do try and repair the bad sectors with WD lifeguard, if its just a small problem will it maybe just break one or two files and then the rest will be okay? or will it ruin the whole thing? 

Thanks for your helpray:


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## raptor_pa (Dec 5, 2008)

The safest way - assuming the diagnostics finishes would be to use data recovery software to copy your data out to another disk. Then you could format the disk and continue to use it. Please start another thread for your issue so we can provide individual support..
Thanks!


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## Cindy62707 (Jan 24, 2010)

I came home to error messages on my computer tonight. Something about IE8 crashing and a problem with the graphics driver too. While I was trying to follow those messages and check for updates I went on about other business and went to attach a file to an email to send. My data is stored on an external WD 1 TB hard drive that is formatted into two 500 MB drives (G and H). H contains my data files while G contains system file backups. I tried to get into H to attach the file and got the error message that it was not accessible and the only option was to format it!!!!! Well I don't want to format my data so I click out of that and get the following message:
Data error (cyclic redundancy check). I can get into G just fine even though it is on the same hard drive but that doesn't do me any good for my data.

I'm not sure where the rest of this thread went to solve this problem. Can someone point me in the right direction. This is my life on this external hard drive that had absolutely no problems until I came home and found that Windows had issues while I was gone.

Thank you!


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## spaciousmind (Jul 8, 2011)

well for me I was able to get all my data back perfectly, after trying a number of things by using a piece of software called Recuva. 
Try it out just make sure to go into options and check 'scan for undeleted files' and 'keep folder structure' before you scan the partition.

In my case the CRC error that windows was throwing up seemed to be a result of my NTFS file system being erased and reverting to RAW (this is what it was showing when I looked in windows disk management). I think this was caused by an electrical problem and have RMA'd it as it wouldnt work again.

Good luck!


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## Cindy62707 (Jan 24, 2010)

spaciousmind said:


> by using a piece of software called Recuva.
> 
> Try it out just make sure to go into options and check 'scan for undeleted files' and 'keep folder structure' before you scan the partition.


After rebooting the computer after the updates finished, the H drive was accessable again so I am trying to copy it over to a different physical external drive. I've been trying since last night but it keeps finding occasional files that it can't copy (and when it does that it comes to a complete stop and waits for me to reply). I don't want to check the skip all box as then I won't have any idea how much I've lost.

So in the meantime, I have downloaded and am running Recuva as suggested. 
I put a check on the "scan for undeleted files" and "restore folder structure" in options like you said but the program is scanning for deleted files anyway. Then it moved on to anayizing files (which says it will take an hour) so I'm not sure what I will end up with. I don't care about files I've purposely deleted on the H drive. I just want to copy and save those that I've been keeping. 

Do you have any idea why it scanned for deleted files when I asked it to scan for undeleted files?

Thanks,
Cindy


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## raptor_pa (Dec 5, 2008)

Unfortunately, with the error you were seeing, your better results will be achieved with the full scan. Any damage to teh directory structure would cause issues. A full scan is always best to ensure you get back the files you really want and you can remove those you don't want.


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## spaciousmind (Jul 8, 2011)

It probably just scans for deleted files anyway by default, after its done you can click on the 'status' column and it will order all your deleted from the undeleted files anyway so you can just choose what you need.


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## Cindy62707 (Jan 24, 2010)

spaciousmind said:


> It probably just scans for deleted files anyway by default, after its done you can click on the 'status' column and it will order all your deleted from the undeleted files anyway so you can just choose what you need.


I did easily find out that I could sort by icon but it is the choosing what I want faster that I am looking for...when you have almost 300 GB of data, it takes forever to individually check one box at a time to choose. I am looking for a way to choose all of the double circle green icons in one quick action. Is that even possible?

Thanks,
Cindy


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## spaciousmind (Jul 8, 2011)

Well, I dont remember there being green icons or anything, but what I did (and this was over 1TB of data) was just first click the status column to sort all the undeleted files, then just select the top of them, and then scroll down and shift+select the bottom of all the undeleted files. . . .. That should highlight them all and then I think you can rightclick on them and tell it to check all selected files or else just transfer all highlighted files over to another drive.
Either way should get you the results you need


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## Cindy62707 (Jan 24, 2010)

spaciousmind said:


> but what I did (and this was over 1TB of data) was just first click the status column to sort all the undeleted files, then just select the top of them, and then scroll down and shift+select the bottom of all the undeleted files


I had already done this. things were sorted correctly. But shift/select from top to bottom didn't "CHECK" anything. I had to check each box one by one by one. 

HOWEVER..... The magic word in the rest of the post "HIGHLIGHT" made me think of clicking on something other than the BOXES.



spaciousmind said:


> . . . .. That should highlight them all and then I think you can rightclick on them and tell it to check all selected files or else just transfer all highlighted files over to another drive.
> Either way should get you the results you need




I selected the NAME of the first file and then shift/select the last file NAME (NOT BOX) and it "HIGHLIGHTED" the entire group of undeleted files. Now I can right click and "recover highlighted" instead of "recover checked"!!!!!

I will hook up a empy drive and see if that can save those files now.
thank you!
Cindy


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