# Drive is Not Accessible: Data Error (Cyclic Redundancy Check)



## jethro05

My 1TB WD Green Caviar has some shared files over the network. Some files were open in the network when my PC was shutting down. When I turned it on again, the whole partition cannot be opened.

First it asks me to format the drive before being able to use it. Of course, I won't format it because its full of data. After that cancelling that dialog, an error message will appear saying: "Drive is Not Accessible: Data Error (Cyclic Redundancy Check)".

Also, the whole drive is now formatted as RAW as opposed to the normal NTFS. I can access the files using TestDisk but i have nowhere to put almost 900GB worth of files.

I had already done the following:

chkdsk (failed because the file format is RAW)
fix MBR, BS, rebuild BS using TestDisk6.12-win (failed again, Write Error)

Recap of symptoms:

RAW file system
CRC error on whole partition

Advanced thanks to everyone who helps.


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## JMPC

Do the files that you're able to access open properly? If the data in good condition, I would consider going to get another drive to copy all of the data off of it. At least you'll have a backup in case something goes wrong with the original drive.


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## jethro05

Yup, all files in good condition so far.

I am also considering backing-up all the files but I have to wait for my friend to let me borrow his external HD or for some money to buy new HD.


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## jethro05

Update: So far, I am not getting any closer to fixing this problem. I deleted the file system table and rebuilt it again using testdisk.

Any idea would be gratefully accepted.


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## Networks

jethro05 your posts are inconsistent ! You first tell us you can get to the files with TESTDISK then you have no where to save them and waiting to get a drive to recover the data to. You were in great shape at that point in time. 

Next you post you deleted the file system table which is a VERY BAD move on your part. What happened in between these posts ? Why did you delete the file system table ?


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## jethro05

Networks said:


> jethro05 your posts are inconsistent ! You first tell us you can get to the files with TESTDISK then you have no where to save them and waiting to get a drive to recover the data to. You were in great shape at that point in time.
> 
> Next you post you deleted the file system table which is a VERY BAD move on your part. What happened in between these posts ? Why did you delete the file system table ?


Sorry, I meant I deleted the data in the partition table so I can rebuild it using TestDisk.

The data is still intact after that maneuver. I was just trying out options as I was not getting any input.


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## Networks

Jethro05, Again your last post indicated you were waiting on a drive to recover the data to. I don't see any additional question in the last post what is the status did you get another drive and recover the data did that fail what is the question ? What input are you waiting for ?


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## jethro05

Well, for one, any input on how to fix the CRC error without using any other drive. I am still searching for solutions other than using another drive to backup and reformatting the partition. Sorry for not being clear.

I've searched around and the only solution that was done so far was backup and reformat. I think it would be possible to fix it without reformatting, I just don't know how.

I am still not able to get a new drive to transfer the data to.


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## Networks

jethro05 CRC Errors are a sign of a hardware problem. In order to perform data recovery you HAVE to have a drive to save the data to. You NEVER want to write back to the drive that is failing or having problems. Don't even think of attempting to save back to that drive at this point in the recovery. Get another drive to recover the data to.


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## jethro05

It's not about the data recovery. I understand that data recovery needs another drive to copy the data to so the information in the failing partition won't be overwritten. 

My hard disk is physically fine. The only thing that is keeping me out of my partition is the CRC error, which resulted when one file was being accessed in the network during shutdown. Maybe there is a way to fix it.


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## Networks

A CRC error tells me the drive is NOT fine ! That's a serious error. Best course is to move the data off to another drive then run WD DOS version diagnostics on the drive then re-partition/format the drive and restore data "IF" WD diagnostics indicate drive is OK.


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## jethro05

ok. I will do that once I have the external HD. Thanks for your patience.

I will update once something comes up.


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## jethro05

Scanned the drive with WD Windows version Extended Test. Networks, you are right. The HD is near failing. Before your suggestion, I thought the HD was fine because before, I only used the WD Windows version Quick Test and it passed it.

Anyway, the test finished prematurely because of the error 08: Too many bad sectors.

I already backed-up the most important data in some smaller HDs, but still hoping to recover the others in the future where I can put them somewhere safer. For now, I disconnected the drive and will only open it again for recovering the remaining data.

I was wrong about the CRC error that can be fixed. Mods can close this thread now. Again, thanks everyone for being patient with me.


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## jethro05

I know this is a bit too late for updates on my case but I just solved the whole problem. Here is what happened while this thread was sitting around un-updated:

I gave up saving the hard disk after everything I have heard and learned about CRC errors in hard drives and failing hard drives. I was planning to return it to WD. Still, I had been stalling because I don't want to lose all the data in the HD, even if all the important files had been recovered. But enough about that.

I recently heard and used HDD Regenerator after a problem with another HD owned by my sister. What I was able to do with the program was identify exactly which sectors are failing and it is also possible to actually recover small amounts of bad sectors. Although the hard disk was not completely rid of bad sectors, what I was able to do was repartition it to avoid the bad sectors.

Following my success with it, I thought I would give it a go with my 1TB. What was surprising was I was able to recover all the bad sectors. So my HD is now fully working again. 

The next part of the problem is recovering the unreadable file system. What I did was use TestDisk to fix the boot record and delete then write a new file system based on scans of the hard disk. After a reboot it is finally working again!:beerchug:

Right now, to make sure everything is really working, I am testing with WD Diagnostics Extended Test. The test will finish in about 2 hrs if no problems occur.


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## Networks

jethro05 said:


> Scanned the drive with WD Windows version Extended Test. Networks, you are right. The HD is near failing. Before your suggestion, I thought the HD was fine because before, I only used the WD Windows version Quick Test and it passed it.


Glad the program worked for you its not always the case however the drive is not ok I would get a replacement if under warranty. I would not trust the drive


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## shilpi

I use windows 7 on my dell laptop.my e drive is not accessible and shows data error(cyclic redundancy check).It requires to be formatted before opening now but i have important data which i could not afford to lose.I have cancelled the chkdsk as it was taking long time to be completed.The entire system has turn sluggish.Please suggest.
Thanks in advance to those who provide their help.


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## jethro05

The best thing to do if you have really important files in your drive, is to either back that data up on another drive or use a data recovery service. Since its a laptop, I am guessing that your hard drive is divided into multiple partitions.

If you want to backup your data yourself, i suggest you use testdisk (search it in google, its a freeware). Save your recovered data in an external storage (cd, dvd or another drive or a thumbnail drive). Do not save it in the same hard drive even if its in a different partition. There is a chance your whole hard drive is compromised. After recovering your files, its better to replace the hard drive completely.

Another path you could take is to use HDD Regenerator. It may or may not work as successfully as what happened on my hard disk. But if you are willing to take the chance, HDD Regenerator can cost a few bucks but if it works it can completely recover all the bad sectors in your hard drive. 

If you decided to use HDD Regenerator, the next thing you should do is rebuild your file system. All HDD Regenerator did is recover the bad sectors that was causeing the CRC error on your drive, but it will not fix the problems that was created by those bad sectors. To completely fix those errors without losing any data, use TestDisk to rebuild your boot sector on that drive.


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## shilpi

thanks a tonne for ur sincere help.I'll try the way out as suggested by you and let you know what happens thereafter.I hope i may not lose my data.


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## mrsmile100

Hi, Jethro. I am having the same problem as yours. Except mine happen when I was trying to transfer some files and the plug got disconnected.

I'm planning to try what you did- first by using TestDisk.

I've just downloaded it but how do I access the files without recovering or modifying them? I couldn't seem to find an option for me to just access the files. I don't want to recover them yet as I am afraid I would ruin my chances of recovering as much files as possible if they are modified.

I hope you see this and will you help me please? thanks a bunch


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## mrsmile100

Anyone? pretty please? Really hopes Jethro or maybe another pro sees this


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## jethro05

Sorry for the late reply. Just got home from vacation.
I will post detailed instructions later today after I get settled down a bit so sit tight for a while.


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## jethro05

Open testdisk_win.exe
Select the proper drive
Select Intel if your using a windows version
Select Advanced
Choose the desired partition if you have more than 1 partition
Select List to view the list of files
Select the file or folder to be recovered then press "c"
Choose a directory to put the recovered file (it is recommended to put it in another physical drive)
Finally, press "c" again to start copying.


BTW, I used TestDisk 6.12 win version.


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## mattduan

hey, how if the CRC error happen to my external HD?? 
what am i suppose to do?? 

anyone can help please!!!!!!


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## mattduan

jethro05, can u help me?? or anyone else??


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## mattduan

*Re: [SOLVED] External Hard Drive CRC error on one folder only?*

hi..spunk.funk..how to run Check Disk on the drive??


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## mattduan

help....help....crc error...how to fix it....please,,,,


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## spunk.funk

Merged your threads together. 
To Run *Check Disk*, go to Start/Run and type *CMD *and press enter. In the *Command Prompt *type the drive letter of the External Drive (ex) *F: *and press enter (ex) *F:\> *now type *chkdsk /R *and press enter. Now type a* Y* for Yes to *Unmount* the drive. *Check Disk* will go through 5 stages. If it does not correct the problem You cannot Fix HDD's. *CRC *errors mean that the drive is failing and there are too many bad sectors on the HDD to recover. Try to recover as much data off of the drive as you can before it stops working entirely.


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