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How To Use CHKDSK (Check Disk) In Windows.

How To Use Chkdsk.

The check disk utility is generally run from the command prompt (although it works exactly the same in PowerShell & Windows Terminal).

Left click on the Start button and then type “cmd”. Right click on Command Prompt (app). Then left click “Run As Administrator”.

You’ll need to click Yes on the UAC pop up that appears.

Launching Command Prompt as Administrator in Windows 10.
Opening Command Prompt as an Administrator in Windows 10.
Launching Command Prompt as Administrator in Windows 11.
Opening Command Prompt as an Administrator in Windows 11.

Enter The Chkdsk Command Into Command Prompt..

When the Command Prompt window opens you need to type in the chkdsk command along with the drive letter of the hard drive that you want to test. Then you’ll need to add what’s called a “switch”.

The switch (also called an option, a parameter or sometimes a flag) tells check disk what it should do. While there are many switches that you could use, the two most useful for home computer users are the /f switch and the /r switch.

Enter the check disk command like this

chkdsk c: /f

Or to use the /r switch, enter it like this

chkdsk c: /r

and then press the Enter key on your keyboard.

chkdsk typed into command prompt window.
Starting a check disk with the /r switch.

What The /f & /r Switches Do?

The /f switch checks the file system on your hard drive and will run through fairly quickly. Generally taking less than 10 mins.

The /r switch checks both the file system and the physical surface of the drive and can run for several hours depending on your computer.

When you’re running a disk check, it’s obviously better to us the /r switch if you can. That’ll check and attempt to repair the whole drive, but it really could run all night.

Cannot Lock Current Drive Message.

After pressing the Enter key you’ll probably see this message appear in the Command Prompt window.

“Chkdsk cannot run because the volume is in use by another process. Would you like to schedule this volume to be checked the next time the system restarts? (Y/N)“

What it means is that chkdsk requires exclusive access to the drive. It cannot operate properly if you (the user) or any programs try to access the files stored on the drive.

To continue, type the letter “Y” and then press the Enter key.

Chkdsk cannot run.
Type the letter Y (for Yes) and press Enter.

Using Chkdsk On Your System Drive.

The system drive is the hard drive that contains your Windows installation. Usually it’ll be labelled as the C: drive in File Explorer. Chkdsk can’t check your system drive while it’s in use, so you’ll need to restart your computer.

  1. Close the Command Prompt window using the X in the top right corner and then restart your computer.
  2. As your computer restarts, you’ll see a prompt to skip the disk check by pressing any key. Don’t press any key on your keyboard.
  3. If you don’t hit a key then chkdsk will begin scanning and repairing your hard drive and file system.


Chkdsk will run on next restart.
Your disk check will begin when the system restarts.


The "Skip disk checking" option.
If you’ve changed your mind, press any keyboard key now to cancel.


Chkdsk scanning drive.
The disk check has begun.

Checking A Storage Drive (Non System Drive).

Chkdsk can check any drive on your computer, not just the system drive. If you need to check other drives within your PC, simply change the drive letter in the command.

For example, on this computer I have a second hard drive, Backup Drive (e:).

To check the file system of the Backup Drive with the /f switch, I’d type

chkdsk e: /f

Or to check the entire drive, change the switch to /r

chkdsk e: /r

After locking the drive, the disk will be checked. Since it’s not the system drive, it can be checked while your still using your computer.


In File Explorer, a backup drive with letter E: is highlighted.
Disk check any drive on your computer.


chkdsk command entered into a command prompt window.
Checking a second hard drive? Simply change the drive letter in the chkdsk command..


Disk checking has begun.
Disk checking has begun.

Your Drive Will Be Unavailable During A Disk Check.

Even though you don’t need to restart your computer to run chkdsk on storage drives (non system drives), they won’t be available for you to use while the check is in progress.
Since chkdsk locked the drive, you won’t be able to access any of the files, folders and any other data on the drive.
A simple notebook.

How To Use Chkdsk.

  • Launch Command Prompt as Administrator
  • Type chkdsk space your drive letter space then add the switch you want to use, either /f or /r
  • For a C drive it would look like this chkdsk c: /r
  • Press Enter on your keyboard.
  • If you’re checking your system drive, you’ll need to press the letter Y and then re-start your computer.

When To Use Chkdsk?

Run chkdsk periodically. Depending on how much use the computer gets, running a disk check 2 to 4 times a year should help to keep both your hard drive and file system in tip top shape.

Ideally you should also run a disk check after what is often called “an unexpected shutdown”. In other words a system crash. Any time your PC suddenly goes off (maybe because it crashed or suddenly lost power), that can cause corruption in the Windows file system. It can also cause physical damage to your hard drive, resulting in bad sectors (unreadable areas of the disk).

Check Disk Can’t Repair A Failing Drive.

If your hard drive is beginning to fail, then replace it as soon as you possibly can. Neither chkdsk nor any other hard drive utility can save or repair failing drives.

Backup your data immediately and then get the drive replaced.

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