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

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.