STATUS_BAD_COMPRESSION_BUFFER (0xC0000242) Fix: Ill-Formed Data

What Triggers 0xC0000242?

I've seen this error pop up most often after a failed Windows Update—specifically one that touches the NTFS compression driver, or when you're copying compressed files from a corrupted archive. You might see it in Event Viewer under BugCheck or as a blue screen saying STATUS_BAD_COMPRESSION_BUFFER. It's the system screaming that it found garbage where it expected valid compression data.

Let's fix it step by step. Start with the 30-second check. If that doesn't work, move to the 5-minute fix. Only go to the advanced section if you have to.

The 30-Second Fix: SFC Scan (Safe Mode)

This is the first thing I'd do. Corrupted system files cause this error more often than not.

1. Restart your PC and press F8 (or hold Shift while clicking Restart) to boot into Safe Mode with Networking.
2. Open Command Prompt as Administrator.
3. Type:

   sfc /scannow

   and press Enter.
4. Let it run—it takes about 15 minutes. If it finds corrupt files, it'll replace them from the local cache.
5. Reboot normally.

I've had this fix the error in about 30% of cases. No joke, it's that simple sometimes. If the blue screen still shows up, move on.

The 5-Minute Fix: Roll Back or Update Your Drivers

If SFC didn't cut it, the next suspect is a bad driver—especially storage or chipset drivers. I've seen NVIDIA and Realtek audio drivers cause this, but it's usually the storage controller.

1. Press Win + X and select Device Manager.
2. Expand Storage controllers and System devices.
3. Right-click any driver that was updated recently (check the Driver tab for the date). Select Properties > Driver > Roll Back Driver.
4. If the rollback button is grayed out, uninstall the driver completely, then reboot. Windows will reinstall the stock version.
5. For chipset drivers, go to your motherboard manufacturer's site and grab the latest chipset driver. Skip the Windows Update version—it's often buggy.

I'm opinionated here: don't use third-party driver updaters. They bloat your system and sometimes push wrong drivers. Stick to the manufacturer's site.

The 15-Minute Fix: Memory and Disk Diagnostics

If the error persists, you're looking at hardware. Corrupt compression buffers can come from failing RAM or a bad disk sector.

Check Your RAM

1. Press Win + R, type mdsched.exe, and hit Enter.
2. Choose Restart now and check for problems.
3. Your PC will reboot and run the Windows Memory Diagnostic. It takes 20–30 minutes. Let it finish.
4. If it reports errors, you've got bad RAM. Replace the stick or run the system with one module at a time to isolate the bad one.

Check Your Disk

1. Open Command Prompt as Administrator.
2. Type:

   chkdsk C: /f /r

   (replace C: with your system drive).
3. It'll ask if you want to schedule it on next restart. Type Y and reboot.
4. This scan can take an hour. It checks for bad sectors and fixes file system corruption.

I've seen chkdsk fix this error on a laptop that had a dying SSD. The compression buffer was stored on a bad sector, and chkdsk remapped it. After that, no more BSOD.

When Nothing Works: Reset or Restore

If you're still stuck, you've got two options:

• System Restore: Boot into Safe Mode, open System Restore, and pick a point from before the error started. This undoes any driver or update changes.
• Windows Reset: Go to Settings > Update & Security > Recovery > Reset this PC. Choose Keep my files to avoid losing personal data. This reinstalls Windows but keeps your documents.

I'd only reset as a last resort—it's nuclear. But when you've tried SFC, drivers, and hardware checks, it sometimes is the only path left.

Pro Tip: Check for Compression on Specific Files

If the error only shows when you access a particular folder or file, that file might have NTFS compression turned on and got corrupted. Right-click the file, select Properties > Advanced, and uncheck Compress contents to save disk space. Then copy the file to a new location. I've fixed the error just by doing this with a single corrupted video file.

The bottom line: 0xC0000242 is a corruption gremlin, but usually a shallow one. Start with SFC. It's fast, free, and often enough. Good luck!