How do I recover files from the FOUND.000 folder and convert .CHK files back?

You ran a disk check, or Windows repaired a drive after a crash, and now your files seem to have vanished. In their place sits a hidden folder called FOUND.000, full of strange files named FILE0000.CHK, FILE0001.CHK, and so on. The good news is that those files are often your missing data in disguise, and in many cases you can recover them without special software.

CHK files are fragments that the Windows Check Disk tool saved when it found pieces of files that no longer had a proper name or folder. Instead of deleting them, Windows stored them safely in FOUND.000, FOUND.001, or a similar folder on the repaired drive. The files lost their names and extensions, but the content inside is frequently still complete.

Quick Answer

Copy the FOUND.000 folder to a safe location first, then work only on the copies. Open each .CHK file by guessing its type from its size and contents, or use a tool that reads the file header, rename it with the correct extension such as .jpg, .docx, or .mp4, and open it to check. Files that open correctly are recovered; damaged or tiny fragments may not be usable.

Why Windows Creates FOUND.000 and CHK Files

When a drive is removed without ejecting, power fails during writing, or part of the file system becomes corrupt, some file pieces lose their connection to a name and location. During a repair, Check Disk scans the drive and collects those orphaned pieces. Microsoft designed this behaviour so data is preserved rather than erased, even if the original structure cannot be rebuilt.

You can read more about how the repair tool works in the Microsoft documentation for the chkdsk command and its repair options. Understanding that page helps explain an important point: chkdsk is a file system repair tool, not a full data recovery program. It saves what it finds, but it does not promise that every fragment is a complete file.

Where to Find the Folder

The FOUND.000 folder is usually at the root of the drive that was checked, for example on a USB stick, an SD card, or an external drive. It is hidden by default, so you may not see it until you show hidden items in File Explorer. There may also be FOUND.001 or FOUND.002 if the drive was checked more than once.

Before You Start: Protect the Original Files

1. Stop writing new files to the affected drive, so you do not overwrite anything.
2. Copy the whole FOUND.000 folder to your computer desktop or another healthy drive.
3. Work only with the copied folder and leave the original untouched as a backup.
4. Make a second copy of any CHK file before you rename or edit it.

This simple step matters because renaming and testing files involves trial and error. If you make a mistake on a copy, the original fragment is still safe and you can start again. Recovery work should never be done on the only copy of the data.

How to Recover Files From CHK Files Manually

Step 1: Show Hidden Files and File Extensions

1. Open File Explorer and open the drive where the repair happened.
2. Select View, then Show, then Hidden Items, so FOUND.000 becomes visible.
3. Also turn on File Name Extensions, so you can see and change .CHK endings.
4. Open the copied FOUND.000 folder on your computer, not the original.

Step 2: Sort the CHK Files by Size

Sort the files by size from largest to smallest. Large files are more likely to be complete photos, videos, or documents, and they are the most worthwhile to recover first. Very small files, especially those only a few kilobytes, are often partial fragments, system pieces, or the leftover ends of larger files. They may never open as a useful file on their own.

Step 3: Identify What Each File Really Is

Every file type has a hidden signature at its start, called a header. A JPEG photo, a Word document, and an MP4 video all begin with different patterns. You can identify many CHK files in three practical ways.

• Use context: If the drive held mostly photos from a holiday, most large CHK files are probably JPEG images, so try that type first.
• Open with a text or hex viewer: Some files show readable clues near the start, such as JFIF for JPEG images or PK for ZIP-based files like modern Word and Excel documents.
• Use a CHK recovery tool: Free utilities scan the header automatically, suggest the correct extension, and rename batches of files for you.

Step 4: Rename and Test One File at a Time

1. Copy one CHK file and paste the copy in the same working folder.
2. Rename the copy by changing .CHK to a likely extension, for example FILE0000.jpg.
3. Double-click the renamed file and see if it opens normally.
4. If it fails, try another likely extension, such as .png, .mp4, .pdf, or .docx.
5. When a file opens correctly, give it a clear new name and move it to a recovered folder.

Testing one file at a time feels slow, but it prevents confusion. Once you learn which extension works for the first few files from a camera or phone, the rest from the same source often follow the same pattern, and the job becomes much faster.

Using a Tool to Convert CHK Files in Bulk

If you have hundreds of CHK files, manual renaming is tiring and slow. Dedicated CHK recovery utilities examine each file header, match it against known file signatures, and rename the files automatically. Some tools also handle files that contain more than one piece of data.

1. Download a reputable CHK recovery tool from its official site and scan it with your antivirus.
2. Point the tool at your copied FOUND.000 folder, never at the original drive.
3. Choose a separate output folder for recovered files.
4. Run the scan and review the suggested file types before confirming.
5. Open a sample of each recovered type to confirm the results are real.

Even with a good tool, check the results yourself. Automatic detection is strong for common formats such as photos and videos, but it can struggle with unusual, encrypted, or split files. For drives that also need broader scanning, our guide to recovering deleted files from a USB drive with free tools covers the next steps when CHK conversion is not enough.

What to Expect From Recovered Files

Set realistic expectations before you begin. A CHK file that was a complete orphaned file often recovers perfectly, with full quality and no visible damage. A file that was only a fragment may open partly, show grey bands in a photo, stop a video halfway, or refuse to open at all. That is not a failure of your method; the missing parts simply were not saved.

Special Cases to Know

• Videos: Large CHK files are often videos. Try .mp4 first, then .mov or .avi. A video may play but lack sound or stop early if it is incomplete.
• Office documents: Modern .docx and .xlsx files are ZIP packages inside. If renaming fails, trying .zip sometimes lets you extract text and images from inside.
• Photos: A partly damaged JPEG may still open in an image viewer and show most of the picture, which is better than losing it entirely.
• Mixed fragments: Occasionally one CHK file contains pieces of two files joined together. Tools can sometimes split these, but manual repair is difficult.

Common Mistakes That Lose Recoverable Data

• Deleting FOUND.000 as junk: Many people delete it because the names look meaningless, and they erase their only saved fragments.
• Working on the original drive: Renaming and testing on the source risks overwriting other recoverable data.
• Renaming everything to one extension: Guessing .jpg for every file guarantees most of them will fail to open.
• Running chkdsk again too soon: Another repair pass before copying the folder can change or replace the saved fragments.
• Giving up after the first failure: A file that fails as one type may open perfectly as another, so test the likely options.

How to Reduce the Chance of CHK Files in Future

CHK files are a symptom of file system damage, so prevention focuses on the causes. Always eject USB drives and memory cards safely before removing them. Replace cables that disconnect randomly, avoid unplugging a drive during copying, and keep a backup of important files in a second location. If one drive repeatedly needs repairs and creates new FOUND folders, treat that as a warning sign that the drive itself is failing and replace it soon.

Conclusion

The FOUND.000 folder is not rubbish; it is Windows keeping your orphaned file fragments safe after a repair. By copying the folder first, identifying each CHK file by its header, size, and likely type, and renaming copies with the right extension, you can recover many photos, videos, and documents yourself. Work patiently, test each result, and keep the originals untouched until you are sure your recovery is complete.

Frequently Asked Questions

Can I safely delete the FOUND.000 folder?

Only delete it after you have copied it elsewhere and confirmed that none of the CHK files inside are needed. Until then, treat it as possible lost data, not as junk.

Why do all my recovered files have the wrong names?

The original names and folder locations were lost when the file system was damaged. Windows saved the content but not the labels, so you will need to rename recovered files yourself.

What if a renamed CHK file still will not open?

Try other likely extensions, open it with a different program, or use a CHK recovery tool that reads the file header. If none of that works, the fragment is probably incomplete or badly damaged.

Are CHK files a sign of a virus?

Normally, no. They are created by the Windows disk repair process after corruption or an unsafe shutdown. Still, scanning any recovered files with updated antivirus software is a sensible habit.

Can one CHK file contain more than one original file?

Yes, sometimes fragments are joined together. Some recovery tools can detect and split combined files, but results vary and part of the data may remain unusable.