Fix STATUS_DEVICE_DATA_ERROR 0XC000009C Bad Sectors

What is STATUS_DEVICE_DATA_ERROR (0XC000009C)?

I know this error is infuriating. One minute you're working, the next you get a blue screen with 0XC000009C or your machine won't boot at all. In my years running a help desk, I've seen this error pop up most often when Windows tries to read a file off a failing hard drive—specifically during boot or when copying large files. It's the hardware equivalent of a scratched CD. The drive has bad blocks—areas where the magnetic surface is damaged or corrupted.

Here's the blunt truth: bad blocks can sometimes be remapped by the drive, but if you're seeing this error repeatedly, your drive is failing. I'm going to walk you through three escalating steps. Start with the first one, and only move to the next if the error persists.

Step 1: The 30-Second Check – Quick Health Look

Before you spend any real time, let's confirm it's not a one-off glitch. Restart your PC. Sometimes a transient read error (like from a power spike or loose cable) triggers this. If the error disappears, you're done. But if it comes back immediately, your drive is crying for help.

While you're at it, check the S.M.A.R.T. status. Most modern drives report this. Download a free tool like CrystalDiskInfo (I prefer it over the built-in Windows tool because it's faster). Open it, look for the Health Status line. If it says Caution or Bad, don't waste time—skip to Step 3. We're past repair.

Step 2: The 5-Minute Moderate Fix – Run CHKDSK

If your S.M.A.R.T. looks okay or you just want to try a repair, run CHKDSK. This command scans for bad sectors and attempts to recover data from them. It's not perfect, but it buys you time.

Open Command Prompt as Administrator (press Win + X, choose Command Prompt (Admin) or Windows PowerShell (Admin)). Type:

chkdsk c: /f /r /x

Here's what each flag does:

/f – Fix errors on the disk.
/r – Locate bad sectors and recover readable info. This implies /f.
/x – Force dismount the drive first (so Windows can work on it).

If you're scanning the system drive (C:), it'll ask to schedule the scan at next reboot. Type Y and restart. CHKDSK runs before Windows loads. It takes anywhere from 10 minutes to a few hours depending on drive size and damage. Let it finish—don't interrupt.

When it's done, check the log: press Win + R, type eventvwr.msc, go to Windows Logs > Application, search for Wininit source. Look for a message that says chkdsk found bad sectors and how many. If it found a handful (like 5-50) and marked them as repaired, you might be okay for now. If it found hundreds, or you get the error again within a week, move to Step 3.

Pro tip: If you're on an SSD, CHKDSK is less useful. SSDs handle bad blocks internally via their controller and don't benefit from this scan the same way. In fact, running /r on an SSD can stress it more. If you have an SSD and get this error, the drive is dying—skip to Step 3.

Step 3: The 15+ Minute Advanced Fix – Replace the Drive

Let's be real: if you've reached this step, your drive is cooked. The only reliable fix for bad blocks is a new drive. I say this as someone who spent years trying to nurse dying drives—it's not worth it. The error will come back, and eventually, the drive will die completely, taking your data with it.

Here's your action plan:

Back up everything you can. Right now. Use an external drive or cloud storage. Don't run CHKDSK again—it can corrupt data further. Instead, use a file-level copy: drag and drop important files to another disk. If the system won't boot, boot from a Windows installation USB (create one using the Media Creation Tool from Microsoft) and choose Repair your computer > Troubleshoot > Command Prompt. Then copy files manually using robocopy or xcopy.
Replace the drive. Buy a new HDD (for bulk storage) or SSD (for speed). I recommend a Samsung or Crucial SSD for reliability. Price per gigabyte is low these days—don't cheap out.
Clone or reinstall. If the old drive is still readable, use a cloning tool like Macrium Reflect Free to clone the old drive to the new one. If you can't clone (too many bad sectors), do a clean Windows install on the new drive and restore your backup.

After replacement, run chkdsk or check S.M.A.R.T. on the new drive to confirm it's healthy. Most new drives show 100% health right out of the box.

What about data recovery services?

If the data is priceless (family photos, business records), and you can't back it up, stop using the drive immediately. Unplug it and send it to a professional recovery service. They have clean rooms and specialized tools. It costs hundreds to thousands, but it's your only shot for data you can't replace.

Final Thoughts

I've seen hundreds of these errors. The ones who tried to ignore it always lost their data. The ones who replaced the drive early slept better. You now have a clear path: check, scan, replace. Respect the bad blocks—they're not lying to you.