How-To Geek

How to Fix Hard Drive Problems with Chkdsk in Windows 7, 8, and 10

wcd_top

Any time you have hard drive errors—or even strange behavior you might not at first associate with a hard drive—Check Disk can be a lifesaver. Here’s a full guide to using the Check Disk tool that comes with every version of Windows.

What Chkdsk Does (and When to Use It)

The Check Disk utility, also known as chkdsk (since that’s the command you use to run it) scans through your entire hard drive to find and fix problems. It’s not a terribly exciting tool—and running it can take some time—but it can really help prevent bigger problems and loss of data in the long run. Chkdsk performs a couple of functions, depending on how it’s run:

  • Chkdsk’s basic function is to scan the integrity of the file system and file system metadata on a disk volume and fix any logical file system errors that it finds. Such errors might include corrupt entries in a volume’s master file table (MFT), bad security descriptors associated with files, or even misaligned time stamp or file size information about individual files.
  • Chkdsk can also optionally scan every sector on a disk volume looking for bad sectors. Bad sectors come in two forms: soft bad sectors, that can occur when data is written badly, and hard bad sectors that can occur because of physical damage to the disk. Chkdsk attempts to fix these problems by repairing soft bad sectors, and marking hard bad sectors so they won’t be used again.

That may all sound very technical, but don’t worry: you don’t need to understand the ins and outs of how it works to know when you should run it.

We recommend running chkdsk every few months as part of routine maintenance along with using a S.M.A.R.T. tool for drives that support it. You should also consider running it any time Windows has shut down abnormally—such as after a power loss or system crash. Sometimes Windows will automatically run a scan during startup, but most often you’ll have to do it yourself. Even if you’re just having strange problems with apps not loading or crashing that you haven’t been able to resolve another way, you might consider checking the disk.

For example: I once had a problem where Outlook suddenly started crashing on me shortly after loading. After a lot of troubleshooting, a chkdsk scan revealed I had bad sectors where my Outlook data file was stored. Fortunately, chkdsk was able to recover the sectors in my case, and everything went back to normal afterward.

If chkdsk does encounter problems—especially hard bad sectors—that it can’t repair, data can become unusable. It’s not very likely, but it can happen. For that reason, you should always make sure you have a good backup routine in place and back up your PC before running chkdsk.

The chkdsk tool works pretty much the same in all versions of Windows. We’ll be working with Windows 10 in this article, so the screens may look slightly different if you’re using Windows 7 or 8, but chkdsk performs the same, and we’ll point out where any procedures differ. We’ll also talk about running it from the Command Prompt, in cases where you can’t even boot into Windows.

How to Check a Disk from Windows

Running the Check Disk tool from the Windows desktop is easy. In File Explorer, right-click the drive you want to check, and then choose “Properties.”

wcd_1

In the properties window, switch to the “Tools” tab and then click the “Check” button. In Windows 7, the button is named “Check now.”

wcd_2

In Windows 8 and 10, Windows may inform you that it hasn’t found any errors on the drive. You can still perform a manual scan by clicking “Scan drive.” This will first perform a scan without attempting any repairs, so it will not restart your PC at this point. If the quick disk scan reveals any problems, Windows will present that option to you. If you want to force it, though, you’ll have to use the command prompt to run chkdsk—something we’ll be covering a bit later in the article.

wcd_3

After Windows scans your drive, if no errors were found, you can just click “Close.”

wcd_4

In Windows 7, when you click the “Check now” button, you’ll see a dialog that lets you choose a couple of extra options—namely whether you also want to automatically fix file system errors and scan for bad sectors. If you want to perform the most thorough disk check, go ahead and select both options and then click “Start.” Just be aware that if you add a sector scan to the mix, checking the disk can take quite a while. It may be something you want to do when you don’t need your computer for a few hours.

wcd_5

If you elect to fix file system errors or scan for bad sectors, Windows won’t be able to perform a scan while the disk is in use. If that happens, you’ll have the option to cancel the scan or schedule a disk check to happen the next time you restart Windows.

wcd_6

How to Check Up On or Cancel a Scheduled Disk Check

If you’re not sure whether a disk check is scheduled for your next restart, it’s easy enough to check at the Command Prompt. You’ll need to run Command Prompt with administrative privileges. Press Start and then type “command prompt.” Right-click the result and then choose “Run as administrator.”

wcd_b

At the prompt, type the following command—substituting the drive letter if necessary.

chkntfs c:

If you have scheduled a manual check of the drive, you’ll see a message to that effect.

wcd_8

If Windows has scheduled an automatic check of the drive, you’ll see a message letting you know that the volume is dirty, which just means it’s been flagged with potential errors. This serves as indication that Windows will run a check the next time it starts. If no automatic scan is scheduled, you’ll just see a message letting you know that the volume is not dirty.

wcd_9

If a disk check is scheduled for the next time you start Windows, but have decided you don’t want the check to happen, you can cancel the check by typing the following command:

chkntfs /x c:

wcd_10

You won’t get any kind of feedback that the scan has been cancelled, but it will have been. This command actually excludes the drive from the chkdsk command for the next start. If you do restart to find that a scan has been scheduled, Windows is also kind enough to provide you with about ten seconds to skip the scan if you want to.

wcd_a

How to Use the ChkDsk Command at the Command Prompt

If you’re willing to use the Command Prompt (or you have to because Windows won’t boot properly), you can exert a little more control over the disk checking process. Plus, if you’re using Windows 8 or 10, it’s the only way to force automatic fixing or bad sector scanning into the mix. Open up the Command Prompt with administrative privileges by hitting Windows+X and selecting “Command Prompt (Admin).” You’ll be using the chkdsk command. The command supports a number of optional switches, but we’re mostly concerned with two of them: /f and /r .

If you just use the chkdsk command by itself, it will scan your drive in read-only mode, reporting errors but not attempting to repair them. For this reason, it can usually run without having to restart your PC.

wcd_11

If you want chkdsk to attempt to repair logical file system errors during the scan, add the /f switch. Note that if the drive has files that are in use (and it probably will), you’ll be asked to schedule a scan for the next restart.

chkdsk /f c:

wcd_12

If you want chkdsk to scan for bad sectors as well, you’ll use the /r switch. When you use the /r switch, the /f switch is implied, meaning that chkdsk will scan for both logical errors and bad sectors. But while it’s not really necessary, it also won’t hurt anything if you throw both the /r and /f switches on the command at the same time.

chkdsk /r c:

wcd_13

Running chkdsk /r gives you the most thorough scan you can perform on a volume, and if you have some time to spare for the sector check, we highly recommend running it at least periodically.

There are, of course, other parameters you can use with chkdsk . So, for the sake of completeness—and your geeky enjoyment—here they are:

C:\>chkdsk /?
Checks a disk and displays a status report.

CHKDSK [volume[[path]filename]]] [/F] [/V] [/R] [/X] [/I] [/C] [/L[:size]] [/B]

  volume          Specifies the drive letter (followed by a colon),
                  mount point, or volume name.
  filename        FAT/FAT32 only: Specifies the files to check for fragmentation.
  /F              Fixes errors on the disk.
  /V              On FAT/FAT32: Displays the full path and name of every file
                  on the disk.
                  On NTFS: Displays cleanup messages if any.
  /R              Locates bad sectors and recovers readable information
                  (implies /F).
  /L:size         NTFS only:  Changes the log file size to the specified number
                  of kilobytes.  If size is not specified, displays current
                  size.
  /X              Forces the volume to dismount first if necessary.
                  All opened handles to the volume would then be invalid
                  (implies /F).
  /I              NTFS only: Performs a less vigorous check of index entries.
  /C              NTFS only: Skips checking of cycles within the folder
                  structure.
  /B              NTFS only: Re-evaluates bad clusters on the volume
                  (implies /R)

The /I or /C switch reduces the amount of time required to run Chkdsk by
skipping certain checks of the volume.

Hopefully, Chkdsk will fix whatever hard drive problems you may have, and you can go back to using your computer normally.

Walter Glenn is a long time computer geek and tech writer. Though he's mostly a Windows and gadget guy, he has a fondness for anything tech. You can follow him on Facebook and Twitter.

  • Published 11/10/16
  • Ben Adler

    Thanks for this informative article.

    Regarding alternative storage mediums, it might be a useful thing to point out that users who have SSD's (which is becoming more popular than traditional hard drives, and perhaps hybrid drives) should research and see if there's a manufacturer-provided storage health utility (I know Crucial provided one... not sure about the other mfg's, but I suspect they have them as well).

    I thought that running chkdsk against SSD's can actually have negative affects long-term, and that the SSD technology tends to self-repair to a degree.

    Your thoughts?

  • I suspect you might be right about SSDs. For whatever that's worth.

  • Walter Glenn

    @BAdler, @anthoney: A good point about SSDs. Physically, they are very different, but they still use the same logical file system. So, it can still be useful to run

    chkdsk /f

    on them from time to time. And that's what Windows will do if it detects an error. It wouldn't be as useful to use the /r switch because they are not prone to hard bad sectors. If parts of an SSD wear out, that would be reported as a bad sector in chkdsk, but in modern drives, the wear leveling features generally map those parts out themselves.

    The idea of negative long term effects stems, I believe, from the first couple of generations of SSD where longevity and excessive disk activity was a real concern. I don't think that's a big issue with modern SSDs.

  • Hmm, they still have a finite number of write cycles so one should avoid any checks that involve writing to the disk. I assume that's the /r you referred to but it's late, I'm too tired to remember with certainty and too lazy to check right now. I also assume unnecessary writes are the long term detriment that was being referred to.

    I admit I have no mental grasp of how long an evo750 will actually last in practice, only that it is finite and will one day use up all its write cycles. So I wouldn't want to waste any on routine disk checks.

    Is it then still readable but frozen with the last data in place? Can this be copied off onto a new drive? Or will it's eventual death take my data with it? Will it warn me when this final stage approaches?

  • Byron Jacobs

    Informative article. Thanks.I have found that Check Disk destruction may be more prevalent than you indicated.

    Your warning to back up everything to protect against Check Disk damage is especially true for USB mounted drives (thumb drives, Micro SD cards, cell phones attached in USB mode, etc.).

    Unfortunately I found through experience that pulling USB-mounted memory out of the computer without using the "Eject" command WILL eventually corrupt it. It can be recovered using certain types of recovery software but if Chkdsk launches and asks to run you definitely want to say NO. Once it runs it destroys the MFT and it cannot be rebuilt with anything I can find. And I worked on recovering an encrypted volume for a month. I never was successful. Fortunately I was able to recreate the data from scratch but it took a very long time.

    So, rule 1) Back up USB-mounted volumes regularly. 2) ALWAYS use Eject in Windows File Explorer or the Task Bar before removing any form of USB-mounted memory; and 3) If Chkdsk asks to run against any form of USB-mounted memory, just say NO and find a recovery tool to recover the data.

More Articles You Might Like