How to Perform a Disk Check on Your Computer
Your hard drive or SSD is doing a lot of quiet work behind the scenes — reading files, writing data, managing system processes. Over time, errors can accumulate: bad sectors, file system corruption, or logical inconsistencies that slow your machine down or cause unexpected crashes. A disk check is one of the most reliable ways to catch these problems early, and it's built right into most operating systems.
Here's how disk checking works, what it actually does, and what shapes the experience depending on your setup.
What a Disk Check Actually Does
A disk check is a diagnostic process that scans your storage drive for two categories of problems:
- Logical errors — file system inconsistencies, such as corrupted file tables, improperly saved files, or directory errors caused by sudden shutdowns or software crashes.
- Physical errors — bad sectors on a hard drive where data can no longer be reliably read or written.
When it finds logical errors, the tool typically repairs them automatically. When it finds bad sectors, it marks them so your OS knows to avoid writing data there going forward. This doesn't fix physical damage — it works around it.
How to Run a Disk Check on Windows
Windows includes a built-in tool called CHKDSK (Check Disk), which has been part of Windows since its earliest versions.
Method 1: Via File Explorer
- Open File Explorer and go to This PC
- Right-click the drive you want to check (usually C:)
- Select Properties → Tools tab
- Under Error Checking, click Check
- Windows may tell you no errors were found — you can still choose to scan the drive
Method 2: Via Command Prompt
For more control, open Command Prompt as Administrator and run:
chkdsk C: /f /r /f— fixes logical errors automatically/r— locates bad sectors and recovers readable information/x— forces the volume to dismount first (useful for secondary drives)
If you're scanning your system drive (C:), Windows will ask to schedule the scan at next restart because it can't scan a drive in active use. This is normal behavior.
Method 3: Windows Security / Storage Health
Newer versions of Windows 10 and 11 also include basic drive health monitoring under Settings → System → Storage → Drive Health, though this is less detailed than a full CHKDSK run.
How to Run a Disk Check on macOS
macOS uses a tool called Disk Utility, which provides a graphical interface for disk diagnostics.
- Open Disk Utility (via Applications → Utilities, or Spotlight search)
- Select your drive from the left sidebar
- Click First Aid
- Click Run to confirm
Disk Utility checks the file system for errors and repairs what it can. For your startup disk, macOS may perform the repair from Recovery Mode to avoid conflicts with files in active use. To access Recovery Mode, restart your Mac and hold Command + R (Intel Macs) or hold the power button until startup options appear (Apple Silicon Macs).
How to Run a Disk Check on Linux 🔧
Linux uses fsck (file system check), which works across various file systems including ext4, FAT32, and NTFS.
Because fsck cannot run safely on a mounted file system, it's typically run:
- At boot — Linux can be configured to run fsck automatically after a certain number of mounts or on a schedule
- From a live USB — boot from a Linux live environment, then run
fsck /dev/sdX(replace sdX with your drive identifier) - On unmounted partitions — for secondary drives you can unmount manually
The exact syntax and options vary depending on the file system type, which you can check with lsblk -f or df -T.
Variables That Affect Your Experience
Not all disk checks work the same way. Several factors shape what the process looks like and how long it takes:
| Variable | How It Affects the Check |
|---|---|
| Drive type (HDD vs SSD) | HDDs have spinning platters where bad sectors are more common; SSDs use wear-leveling and may show different error patterns |
| Drive size | A 4TB HDD with /r enabled can take several hours to scan |
| File system type | NTFS, exFAT, HFS+, ext4 each have their own tools and repair behavior |
| OS version | Older Windows versions have fewer automatic error-detection features |
| Drive health | A drive showing SMART errors alongside file system errors may be near failure — no disk check will fix hardware deterioration |
When Disk Checks Aren't Enough 🛑
A disk check is a diagnostic and repair tool — not a recovery tool and not a replacement for monitoring overall drive health. If your drive is generating SMART errors (Self-Monitoring, Analysis and Reporting Technology), those are hardware-level warnings that a file system scan won't resolve.
Tools like CrystalDiskInfo (Windows) or the smartmontools package (cross-platform) can read SMART data to give you a broader picture of drive health beyond what CHKDSK or Disk Utility show.
The Gap That Depends on Your Setup
How often you should run disk checks, which method fits your workflow, and how urgently you should act on the results — those questions don't have universal answers. A home user on a years-old HDD is in a different position than someone running a fresh SSD on a modern OS with automatic error monitoring enabled. The tools are the same; what they mean for your next step depends on what they find and what you're working with. 💡