> Recover data after CHKDSK

CHKDSK Deletes Your Data? Now Recover Them in Few Steps

Since you are here, it's likely that recently you ran CHKDSK and finally found lots of files get lost. Actually, you are not alone to this issue. I picked out 2 similar cases from the internet:

Case 1: When Vista told me to run CHKDSK for my external hard drive, I foolishly did it. Then I saw a lot of "deleting index..." messages and I knew it was bad news. After CHKDSK, a whole lot of files, including personal backups, photos, videos, and some other files, got lost. Is there a good way to get these deleted data back?
……Macko from GetData forum

Case 2: On my computer with Win7, after only one execution of CHKDSK, all files disappeared on my secondary HD (around 500Gb of very important data). I read the CHKDSK log file and it has found many mistakes on the HD including on the MFT. Is it possible to recover missing files as well as MTF?
……Guuk from Superuser

Under such a circumstance, most of you would be concerned about these or some of these topics: what is CHKDSK or what does it do, when and how to run CHKDSK, why files get deleted after CHKDSK, and how to recover CHKDSK deleted data.

Now, let's talk about these questions in detail.

What Is CHKDSK, Exactly?

Microsoft says CHKDSK creates and displays a status report for a disk based on the file system. It also lists and corrects errors on the disk. Used without parameters, CHKDSK displays the status of the disk in the current drive.

Wikipedia says CHKDSK is a system tool in DOS, OS/2, and Windows to verify the file system integrity of a volume and fix logical file system errors. It can also check the disk surface for bad sectors and mark them.

In my opinion, CHKDSK is a Windows built-in utility to report disk/volume state if we run it without giving any parameters, and repair problems caused by, or related to, bad sectors, system errors, cross-linked files, directory errors and lost file clusters if we use it by specifying parameters, like /f, /r, and /x. Functions of commonly used CHKDSK parameters are as follows:

/F: Fixe errors on the disk. The disk must be locked. If CHKDSK cannot lock the drive, a message appears that asks you if you want to check the drive the next time you restart the computer.
/R: Locate bad sectors and recover readable information. The disk must be locked, too. In addition, /r does things /f does, but it is more multifunctional and powerful, and the only defect is that it costs much more time.
/I: Use with NTFS only. Performs a less vigorous check of index entries, reducing the amount of time needed to run CHKDSK.

For more parameters, please see Microsoft's CHKDSK Introduction. Then, let's talk about when we need to run CHKDSK as well as how to use such an utility.

"Running CHKDSK is highly recommended if your drive has file system errors, directory errors, or even bad sector issues."

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When and How to Run CHKDSK Properly

After a system crash or improper shutdown, Windows might force a CHKDSK the next time you restart computer, which is to fix any disk-related issues that may have resulted from the crash or shutdown. At this time, you'd better do as system suggests.

run chkdsk after system crash or improper shutdown

When you open a file, you might receive an error message saying the file is corrupted and asking to run CHKDSK utility. Of course, such an error message might pop up from the lower right corner even if you are doing nothing. To deal with this issue, you can choose to delete the corrupted data or run CHKDSK to fix it. As long as the corrupted data is not that important, just delete it. On the contrary, run CHKDSK utility to fix the problem.

run chkdsk when files corrupt

If Windows asks you to run CHKDSK utility frequently and report corrupt on different files, it's likely that there are serious problems on your hard disk, and it may fail before long. Then, it's wise to backup the entire hard disk in case of any data loss, and you can view the post Copy Disk to get operating steps.

Of course, even if Windows does not ask you to run CHKDSK, you can also do it manually when you think it's time to check disk.

Then, let's see how.

Here, we will introduce 2 simple ways:
1.Enter Windows Explorer, right click the drive you want to check, click "Properties", click Tools tab, and choose Check now. Then, you'll get 2 options:

run chkdsk in windows explore

Automatically fix file system errors: with checking this option, CHKDSK will scan and fix system errors it found.
Scan for and attempt recovery of bad sectors: with checking this option, CHKDSK will scan and try to recover information from bad sectors, but this is more time-consuming.

After making your decision, just click Start to check the appointed drive. Nevertheless, if a process is using the drive you'll be checking, you may receive the following message (for system drive):

can't run chkdsk when the drive is in use

Or this one (for data drive):

can't run chkdsk for data partition

Under these situations, you have 2 choices:
  • Click on Cancel, close any file or program that uses this drive, and try again. For data volume only.
  • Tap on Schedule disk check, and the checking process will be performed the next time you start your computer. For both system volume and data volume.

2.You can also run CHKDSK in command line: type command prompt in Search programs and files box after clicking Start, and run this program as administrator:

run chkdsk in command prompt

Supposing we are going to check drive D to recover system errors, we need to type CHKDSK D: /f and press Enter key. Nevertheless, you may receive the same error messages if the drive is in use. Just do as the former part suggests.

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At this time, some of you might ask why an error fixing tool results in data loss. That's so strange!

Now read the third section to get the answer.

Your Files Might Get Lost due to CHKDSK

As we know, CHKDSK examines disk space and disk use by testing the File Allocation Table (FAT) or the New Technology File System (NTFS) for broken, missing or corrupt files that impact your computer's ability to function properly. Once errors are found, it will fix them if we specify /f or /r command-line option. Nevertheless, repairs usually change a volume's file allocation table (for FAT partition) or master file table (for NTFS partition). If the repairing process is interrupted or affected by any other change, information on FAT or MFT might be lost or even corrupted, which could lead to data loss. Please see But luckily, for this kind of lost files, we might be able to recover them. As to the specific recovery method, we will introduce it later.

Further reading:
A partition consists of 2 parts, including data area and file system area. Properties, such as file size, file type, and creating time, are stored in file system area (FAT or MFT), and real files are saved in data area. Commonly, deleting a file just modifies file allocation table of FAT partition or main partition table of NTFS partition, as well as other parts in file system area, which makes it possible to recover deleted data. For more details, please see How is a File Deleted in Window.

In addition, a malware infection like virus, spyware, and Trojan horse is always making our files corrupted and unreadable, and these files cannot be recovered by CHKDSK. Once the utility finds such a type of infected or corrupted files, it will delete them. Of course, there is no need to recover originally corrupted data unless you are able to repair them.

Moreover, CHKDSK will delete files holding invalid file name in directory or delete corrupted index entries and attribute records.

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This section just partly explains why data get lost after CHKDSK, and in fact there might be other reasons we haven't found. If you know other ones, we much appreciate that you share them with us.

Then, let's get to the section users care about most.

2 Ways to Recover Data after CHKDSK

trick Trick:
Before doing any recovery, please make a backup for your drive where data loss appears in case of any accidents. And you can refer to the post Copy Partition to get detailed steps.

Recover CHKDSK Deleted Data from Found.000 Folder

When CHKDSK is going to delete files, it may send you a confirmation message similar to the following:

20 lost allocation units found in 5 chains.
Convert lost chains to files?

If you press Y, Windows will save each lost chain in the root directory of your drive as a file with a name in the format Filennnn.chk. When disk check is completed, you can check these files to see whether they contain data you need. If you press N, Windows just fixes the disk, but it does not save the contents of the lost allocation units.

So, firstly you can go to the root directory of your drive to see if there is a found.000 folder which is hidden by default.

To view hidden folders, you need to navigate to Folder and search options > View > Hidden files and folders, and then fill in the bubble for "Show hidden files, folders, and drives".

Then, you will see such a folder:

found.000 folder

Open this folder and you can see lots of files with .chk extensions:

.chk files

Definitely, these files are inaccessible since their extensions have been changed. If you know exact extension of each file, changing .chk of every file to the correct extension may restore them. For example, if the first file is a word document, to change .chk to .doc or docx may make the word document available again. But in fact few people can remember extensions of each file especially when there are lots of lost files, so this method is infeasible.

But luckily, there are third party tools to recover CHK files by checking the headers of these files and identifying what type a file is and what its original extension should be. Just search such a kind of tools on the internet, and some of them are even for free.

Nevertheless, what if no Found.000 folder is found in root directory of your drive or you haven't found desired data from this folder? Under this situation, to make use of data recovery software might be a good choice.

Recover CHKDSK Deleted Data with Data Recovery Software

Firstly, download and install MiniTool Power Data Recovery to your computer, and then launch the program to get its main window.

Tip: do not install the program to the drive where data loss appears, otherwise lost data could be overwritten, causing lost data lost forever.

minitool power data recovery main window

There are 4 modules on the main window, and we need to choose "Damaged Partition Recovery" to restore files deleted by CHKDSK.

recover data select a partition to scan

Then, select the partition where data loss emerges and click on "Full Scan". Some of you might ask why choose Full Scan rather than Open. That is because the former will deep scan your device, which gives a bigger chance for data recovery. After successful scan, all data it found will be shown:

scanning results

Firstly, we suggest choosing a partition named by number to look for needed files, for example #1 (NTFS), since original name of each file in this kind of partitions will be reserved. However, if you fail to find desired data from these partitions, select the All RAW Files partition to recover data.

trick Trick:
If there are so many files found, you can make use of Preview, Find, and Filter features to filter needless files. Please see How to Work with Found Data to get more details.

Once finding needed files, check them and click "Save" button to save them to another storage device.

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Don't save data to its original place, for it may overwrite lost data. In addition, the free version of Power Data Recovery just allows users to recover 1GB data for free. If you want to recover more files, you may need to purchase a license.

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Kindly reminder:
data recovery software will fail to recover lost files if they have been overwritten by new data. It is also unable to repair corrupted files, so data recovery software is in no use if the lost files are corrupted before the loss or corrupted due to any other factor after the loss. In these cases, you'd better ask professional data recovery companies for help.

At the end of this post, let's see some tips.

2 Tips on Running CHKDSK

The following 2 tips might be useful to help you avoid data loss caused by running CHKDSK:
1.Create a full backup for your drive before running CHKDSK in case of any accidents.
2.Do not interrupt the checking process, as doing so can compromise the integrity of the hard drive. Scans should never be started if there are factors that could lead to power outages.

If you are still unclear of CHKDSK or CHKDSK related problems, just feel free to contact us.