How to Run a Disk Check on Windows (and When You Should)

Your computer's storage drive works hard — reading, writing, and organizing data thousands of times a day. Over time, that activity can lead to file system errors, bad sectors, or minor corruption that quietly degrades performance. Running a disk check is one of the most reliable ways to catch and fix these issues before they turn into data loss.

Here's how it works, what your options are, and what affects the process on your specific setup.

What a Disk Check Actually Does

A disk check scans your storage drive for two main categories of problems:

• File system errors — These are logical issues: broken file paths, mismatched directory entries, or incomplete writes caused by crashes and improper shutdowns. Windows tracks files using a file system (typically NTFS), and that structure can develop inconsistencies over time.
• Bad sectors — These are physical or logical spots on the drive that can no longer reliably store data. A full scan attempts to read every sector and, where possible, marks damaged areas so the OS avoids writing to them in the future.

The tool built into Windows for this job is CHKDSK (Check Disk) — a utility that's been part of Windows for decades and remains the standard approach.

How to Run CHKDSK on Windows

There are two main ways to run a disk check: through File Explorer or via the Command Prompt.

Method 1: Through File Explorer (Easier)

1. Open File Explorer and go to This PC
2. Right-click the drive you want to check (usually C:)
3. Select Properties → click the Tools tab
4. Under Error checking, click Check
5. Windows may say no errors were found and ask if you want to scan anyway — click Scan drive to proceed

This method runs a basic scan and is suitable for most everyday situations.

Method 2: Command Prompt (More Control) 💻

1. Search for Command Prompt, right-click it, and select Run as administrator
2. Type the following and press Enter:

chkdsk C: /f /r 

What those flags mean:

If you're scanning the C: drive (your active system drive), Windows can't scan it while it's in use. It will ask to schedule the scan for the next restart — that's normal. Type Y and reboot.

For secondary drives (D:, E:, etc.), the scan usually runs immediately without a restart.

Method 3: Windows Security / Settings (Windows 10 and 11)

Windows 10 and 11 also include a Drive Health monitor under Settings → System → Storage → Drive Health (for supported NVMe and SSDS with SMART data enabled). This isn't a full CHKDSK scan, but it gives a quick read on overall drive condition.

HDD vs. SSD: Does It Matter Which Drive You Have?

Yes — and this is an important variable. 🖴

Hard disk drives (HDDs) have spinning magnetic platters, making them genuinely susceptible to physical bad sectors from wear, vibration, or age. Running CHKDSK with /r on an HDD can take hours on large drives and is a worthwhile regular practice.

Solid-state drives (SSDs) work differently. They don't have moving parts, so traditional bad sector scanning is less relevant. SSDs manage wear through wear leveling and their own internal error correction. Running /r on an SSD is generally unnecessary and adds write cycles without meaningful benefit. For SSDs, monitoring SMART data through tools like CrystalDiskInfo tends to be more informative than CHKDSK.

When Should You Run a Disk Check?

There's no universal schedule, but certain situations make a disk check worth doing:

• Your PC crashed or lost power without a proper shutdown
• You're seeing file corruption errors or programs failing to open
• Windows is running noticeably slower without an obvious cause
• You're getting blue screens tied to disk-related error codes (e.g., NTFS_FILE_SYSTEM)
• You're preparing to reinstall Windows or clone a drive
• A drive is making unusual clicking or grinding sounds (though at that point, data backup is the priority)

Windows 10 and 11 also run automatic maintenance that includes basic disk checks in the background, so you may not need to intervene as often as older Windows users did.

What Affects How Long a Disk Check Takes

Several factors determine whether a scan finishes in minutes or several hours:

• Drive size — A 4TB HDD with /r can take 4–8+ hours
• Drive health — More errors or bad sectors = longer scan time
• Interface speed — SATA drives are slower to scan than NVMe
• Drive type — SSDs complete scans significantly faster than HDDs
• System load — Scans during startup (on locked system drives) tend to run faster than background scans

Reading the Results

After CHKDSK finishes, it reports what it found and fixed. Key lines to look for:

• "Windows has scanned the file system and found no problems" — You're clear
• "X KB in bad sectors" — Physical damage was found; monitor this drive closely
• "Errors fixed" — File system issues were repaired

You can also view CHKDSK results after a restart by opening Event Viewer → Windows Logs → Application, then filtering for Wininit as the source.

The Variable That Changes Everything

Running CHKDSK is straightforward — the steps above work for most Windows users. But what the results mean, how urgently you should act on them, and whether a disk check is even the right diagnostic tool for what you're experiencing depends heavily on your specific drive, its age, your operating system version, and what symptoms led you here in the first place. A single bad sector on a 7-year-old HDD tells a very different story than the same finding on a drive installed three months ago.