I have dealt with many hard drive failures in the past, and most of the time it was the result of bad sectors. Other times it was a complete failure where the hard drive wouldn’t even power up. In the latter instance there isn’t much you can do to retrieve your data.
As for bad sectors, you may still be able to retrieve your data, if you have the right tool. It is difficult to copy data from a damaged hard drive, especially in Windows since it would usually stop the copy when it encounters a bad sector. Recently, I managed to retrieve over 5GB of data from a hard drive with many bad sectors, and in this post I’ll tell you how I did it.
What are Bad Sectors?
Hard drives consist of several circular platters that use magnetism to store the bits of data. Each platter is then divided into tracks, which run in a circular pattern around each platter. Each track is broken into many smaller pieces called sectors. To reduce overhead, sectors are grouped together in clusters.
A bad sector occurs when there is physical damage to a part of the hard drive. Modern hard drives are created with many spare sectors. When the disk controller’s firmware in the hard drive detects a bad sector, it remaps that sector to another physical sector on the hard drive. This remapping is transparent to the operating system. Once the hard drive runs out of space sectors, meaning it can’t remap existing bad sectors, the operating system will begin to detect these bad sectors. Once detected, the operating system will mark these sectors to prevent them from being used in the future.
As the hard drive accumulates more bad sectors, you may begin to lose data, have your system crash more frequently, or have your entire system become very slow and unresponsive. This means that you should be backing up your data and replacing your hard drive.
How do you go about backing up your data, if you already have bad sectors? Windows doesn’t handle copying data from a hard drive with bad sectors very well. Actually, it doesn’t handle it at all. For that you need to install another tool. The steps below outline how I managed to recover data from a defective hard using such a tool.
TestDisk from CGSecurity
When I recently received a hard drive with many bad sectors I decided to try and recover some of the data. The important thing is to see if the hard drive was still able to be powered, and that both the BIOS and Windows was able to detect the drive. As luck would have it, I was able to boot up my computer and detect the drive. Here is what I did to get the data:
- I connected the problem drive as a slave to an existing system. After configuring the BIOS for the new drive, I loaded Windows. Windows took much longer to load because of the defective drive, but it eventually was able to load.
- Next I opened up my web browser and navigated to the TestDisk page on the CGSecurity wiki web site.
- Once I downloaded and installed the tool, I started up the application.
- The first screen prompts for action about log files. I selectedt Create and pressed Enter.
- The next screen lists all hard drives detected by the tool on mysystem. I simply highlighted the hard drive with the problem and pressed Enter.
- Next I selected the partition type. For PCs select Intel, for other’s you would select the corresponding option. Since Intel was selected, I pressed Enter.
- I was now presented with a list of options. To copy the data I needed to select Advanced and then pressed Enter.
- The next step listed the various partitions on my hard drive. I selected the partition that contained the data I wanted to copy and pressed Enter.
- I know saw the partition I selected at the top. At the bottom was a menu. In the menu I highlighted List and pressed Enter.
- A list of directories on the partition was now displayed. I selected a directory I wanted to copy and pressed c.
- When I was prompted to perform the copy, I pressed Y to begin the copy.
- I was informed when the copy has completed, and whether any errors occurred. From this point I could have selected another file or directory to copy.
Using the above steps I managed to copy over 5GB of data very quickly from a hard drive that had many bad sectors. I haven’t checked all the data, but the files I did check opened up without an issue.
Have Your Say
- Have you lost data because of a hard drive crash?
- Were you able to restore data from a hard drive with bad sectors?
Tags: Bad Sectors, Data Recover, hard drive crash
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on September 4, 2008 at 4:23 am
Paul,
Thanks for the lesson in hard drives work. There’s one point that should be made to readers which I don’t think came across real clear.
Don’t wait until your hard drive starts to fail before backing up your data. I’ll be the first to admit I’m guilty of this as well, but your article came across as saying to wait until you receive errors before backing up.
on September 4, 2008 at 6:12 am
Paul,
I had a problematic 15 GB disk 5 years back. I tried to recover the data. but i wasn’t aware of any tool. I used norton disk doctor to find out the bad sectors.
Finally one day i threw the harddisk in the bin.
Do you know any tool that can check whether the harddisk has already got a badsector but using one of the spare sector?
Let me know.
Nihar
on September 4, 2008 at 8:09 am
@Bcarter: I agree that you shouldn’t wait until you have a hard drive failure before you backup your data. I have written many posts in the past regarding backup, and I will include those links in this post. I just wanted to concentrate on recovering your data in this post.
@Nihar: There are several tools that could help find bad sectors, which I am going to write about in the next post, including the one that I used.
on April 26, 2009 at 11:55 pm
I have a question. I have an old 100 gig hard drive. It got a nasty virus. Today, I tried to slave the drive on another system, but I was not able to view the drive. Also, If I left it plugged in my system locks up. I got the device manager to find the drive, but I couldnt access the files on the drive. Do you think this program you describe would work for this. Thanks
on April 27, 2009 at 8:00 am
It could work. I once read a drive when Windows wouldn’t even read the partitions. The program was able to find the missing partitions and I was able to then copy over the files.
on September 9, 2008 at 10:58 pm
Paul, thanks for saving my 5 gigs. Glad you could use the experience for your site. Now, any explanation on how my backup hard drive failed at the exact same time as my main drive? Weird huh? Maybe you can recover a few gigs from my back up drive next!
on September 10, 2008 at 8:34 am
@Martini: No problem. I’ll have to get your backup drive and have a look. Any problems that occurred with your computer may have affected both drives at the same time, causing both drives to eventually report bad sectors. I haven’t looked at your backup drive yet, but I’ll see what is wrong with that one.
on January 5, 2009 at 7:22 pm
I just lost 2-3 large PST files when Windows XP crashed while OUTLOOK was loading. The system did a memory dump and when windows rebooted it did a chkdsk and found un-readable segments on the disk…..it realocated these to “bad sectors” and I cannot even find my PST files.
I want to try to use cgsecurity.org/wiki/TestDisk as a file recovery solution.
Can anyone please comment on this?
Thanks – Greg
on January 6, 2009 at 9:07 am
Have you tried to repair the drive? Is Windows taking longer to load and access?
on January 10, 2009 at 4:55 pm
I too am wondering about cgsecurity.org/wiki/TestDisk. I am getting the blue screen, cannot boot up. Tried the chkdsk /r and it tells me that there is one or more unrecoverable…. I’m looking at getting another HD and settiing the bad one up as a slave to try to get some of the data up.
Thoughts??
on February 28, 2009 at 11:53 am
I was reading your steps. Seems I got up to the point where I hit c and nothing happens. I can view the files, but I can’t copy them. I’m using the DOS version of the program tho
on February 28, 2009 at 11:53 am
I was reading your steps. Seems I got up to the point where I hit c and nothing happens. I can view the files, but I can’t copy them. I’m using the DOS version of the program tho
on February 28, 2009 at 11:53 am
I was reading your steps. Seems I got up to the point where I hit c and nothing happens. I can view the files, but I can’t copy them. I’m using the DOS version of the program tho
on May 2, 2009 at 3:32 am
I’m trying to use this tool to recover what’s left of a 750GB HDD with lots of bad sectors in it…
I had some hope this could be a little faster then other programs “…Using the above steps I managed to copy over 5GB of data very quickly from a hard drive that had many bad sectors…”
Ok… i think either you were lucky (few bad sectors) or i’m a very unlucky fellow… my PC is running the program for 48h and it displays for the remaining time… 1277h31m24 …
HDD data is +/- 250GB on the 750GB HDD.
on May 4, 2009 at 8:14 am
I think I you were right about the number of bad sectors. The hard drive I used had very few, which is probably good because it means that I was able to retrieve the data just as the hard drive was going. The hard drive I was checking was also a lot smaller than 750GB and obviously had much less data.
Did the tool eventually retrieve the data from the hard drive? Were there many bad sectors?
on May 5, 2009 at 1:12 pm
I gave up when more than 300 Bad Sectors were found (and no noticeable end time reduction was shown … )
By the time i gave up the tool recovered +/- 1500 files… most of them “unharmed”, although unfortunatly the names weren’t kept, so extra work.
Nevertheless, i think the tool works fine… it does perform the same way as a lot of professional software, with the big advantage that it’s free.
Thanks for your interest on my case… As the harddisk is in the warranty perior i will return it to the seller…
on July 25, 2009 at 10:06 am
Hi How ya going?
ok i am really stuck.
I have a 400gb drive that i use as my backup drive… save all my stuff on there…. i did a format on my computer and was going to reinstall all my stuff back on my computer when one of my kids knocked the backup drive off the table…. i am unable to get it to detect now… its making noise and yeah sounds like bad sectors… any way i can fix this?
Thanks for your time
on July 25, 2009 at 12:29 pm
OK got the drive to work but is still not showing as a drive in windows….
its in a USB case.. when plugged in will show new hardware and say mass storage device… then will say device ready for uses… but still no show in my computer or in computer management / disk management
TestDisk can see it but not as the 400gb… its showing as a 2199 GB???
i have run the test… not having much luck….
Any help would be good seeing i have over 5 years of stuff on this drive….
on November 3, 2009 at 12:13 pm
how to open or mount dd image file on windows?? I was able to get lot of data but can’t open it. any help??
on November 14, 2009 at 6:08 pm
My usb flash is not functioning on any cpu. It states it’s not readable and asks if I’d like to reformat. I attempted a quick reformat in hopes of then using a usb flash recovery download to scan the drive for data but can’t do that without the simple reformat. In fact it won’t even reformat normally and says the “disc in drive e can’t be formatted.” I attempted to use the above-mentioned “testdisc” program and while it ran through the disc and saw it as a “generic usb,” it kept finding “errors reading sectors” and it produced none of the files that were on the usb flash drive previously. I’m at my end with this and wonder if there are any suggestions. Just trying to recover some data and going crazy. Thanks for any suggestions.
on November 14, 2009 at 6:09 pm
My usb flash is not functioning on any cpu. It states it’s not readable and asks if I’d like to reformat. I attempted a quick reformat in hopes of then using a usb flash recovery download to scan the drive for data but can’t do that without the simple reformat. In fact it won’t even reformat normally and says the “disc in drive e can’t be formatted.” I attempted to use the above-mentioned “testdisc” program and while it ran through the disc and saw it as a “generic usb,” it kept finding “errors reading sectors” and it produced none of the files that were on the usb flash drive previously. I’m at my end with this and wonder if there are any suggestions. Just trying to recover some data and going crazy. Thanks for any suggestions. Thanks
on February 28, 2010 at 3:44 pm
I used this program to recover data from a WD 320 Gb HD that four other programs could not even see. Great program!! It was very fast for me. I recovered 7.14 GB of data in less than half an hour with very few errors. If only the rest of life was this easy.
on September 10, 2010 at 4:57 pm
I followed this article and was able to copy 90% of files from a crashed 300GB hard drive. Thanks very much. During the copying, I could use “dir” to check the progress. For these 10% files TestDisk failed to copy, TestDisk was just hanging forever at a point where “dir” showed the same file size and no progress in copying. I had to kill the TestDisk job in Windows Tesk Manager. What were the problems that hang TestDisk during copying? Is there a way to solve them? Thanks.
on September 12, 2010 at 11:27 am
Perhaps TestDisk came across a file it was trying to read, but couldn’t because of damage to the hard drive? In a case such as that you may want try another utility such as HD Regeneration to see if it can recover the data.
on April 4, 2011 at 6:25 pm
FANTASTIC!!! My hard drive was grinding so bad that I was ready to toss it and came across your website….I was able to recover everything and couldn’t be happier!! Best software ever!!!
on April 5, 2011 at 8:30 am
I’m glad you were able to recover everything.
on August 27, 2011 at 8:11 am
When I press “C” after coming to the directory I want to be copied, it says “Can’t create file!”.
Same happens for ANY file/directory I try to copy. Any help would be appreciated.
on August 27, 2011 at 5:42 pm
Do you have permission to write to the directories?
on August 29, 2011 at 12:28 am
hi,
I tried to format my C drive and install Windows7 OS. Earlier i had Vista home basic.
I saved all my data in partition f: and took back up of only C:
After successfully partitioning c drive and installing Windows 7, i tried to open F:
but it shows it is empty and no data is seen now. it showed bad sector error.
Lost all my data..
plssss help me recovering the data.
on August 29, 2011 at 1:22 am
also, i tried all the steps mentioned in the article with testdisk.
when selected my F: and listed directories, no directories were displayed.
pls help me.
on November 22, 2011 at 8:07 am
many thank’s..
on November 25, 2011 at 4:54 pm
Thx. This advice really did some help.
on January 9, 2012 at 7:20 am
Hi Paul,
I have a 1 TB Seagate hard disk which I’m using since last 3 years. Day before yesterday, it showed some problem but due to lack of available space on my laptop, I could not transfer data.
The very next day, it started responding badly, and at times it got stale. I had to forcefully disconnect it and restart laptop to get things going. In the evening I tried to copy the content to another external hard disk, but I was not able to access the content. Even I’m not able to click any content on the drive, I can only view them. The size of the drive and free space are correctly displayed.
I executed chkdsk and Seagate data recovery tool, both got stuck at 70% and kept giving messages “bad sector xxxxxx” and “file segment xxxx unreadable”.
I have got prized memories of my life stored there along with many sensitive information.
How can I save the data stored in it ?
Please guide, thanks a lot !