How to fix Cyclic Redundancy Check (CRC) data errors

If you’re receiving a Cyclic Redundancy Check (CRC) error, there are steps you can take to determine where in the system the issue lies and then resolve the error. It’s essential to understand what a Cyclic Redundancy Check error is and what it means for you and your system.

What is a Cyclic Redundancy Check Error?

When data enters your system, they’re assigned a check value, which is a kind of mathematical summary of the file’s content. This check value adds no new information to the file (and is thus redundant). When your system retrieves the file, it repeats that calculation and compares the two results. If the values are different, the data is corrupt. The system creates a warning.

No one likes seeing an error, especially a file-based error, but the Cyclic Redundancy Check is an essential feature of modern file-based systems. It’s a valuable tool for assessing potential errors or corruption in files.

Cyclic Redundancy Checks ensure that data passed through networks or communication channels isn’t corrupted. The system assesses the value of the file when it enters the system and again before opening.

It’s important to note that while there may be an issue with a specific file, the Cyclic Redundancy Check Error can also mean a problem is present in the hard drive where the file resides.

What can cause a data error during a Cyclic Redundancy Check?

Many things can cause a Cyclic Redundancy Check data error. Usually, you’re looking at a file that has become corrupted or damaged. It’s important to note that while there may be an issue with a specific file, the Cyclic Redundancy Check Error can also mean a problem is present in the hard drive where the file is stored.

If your hard drive cannot read the file, this will cause a Cyclic Redundancy Check error. The reason your hard drive couldn’t read it is the source of the problem. It could be a file that’s simply corrupted or unusable, in which case, the file itself is the source of the problem. If the drive can’t read the file because of the drive’s ability to read the file or the sector of the drive the file lives on, then the issue is the hard drive itself. A hard drive problem is a much more severe issue.

Fixing a Cyclic Redundancy Check Error

If you only see the Cyclic Redundancy Check error on a single file, the file itself is likely the issue. To determine whether the file or the drive is at fault:

• Try copying the file to another drive, then open the file or program. If you cannot copy the file, the file itself may be the issue.
• Try opening or using other files from the drive that the original Cyclic Redundancy Check error occurred on.
• If the drive is causing the error, try a different connection cable to determine if the issue might be a faulty SATA or other cable.

Warning: Before attempting any fixes, you should try backing up the drive, as many fixes can result in the loss of files or require a complete wipe or reformatting of the drive.

Perform a CHKDSK scan (Windows)

Checkdisk is a built-in Windows utility that will scan the drive in question and fix detected errors automatically. To access the CHKDSK utility:

1. Open Windows Explorer, and right-click on the drive you wish to check.
2. Choose “Properties” from the menu.
3. Click the “Tools” tab.
4. Choose “Error Checking” by clicking on the “Check” button.
5. Windows will launch the check disk process.

Alternatively, you can also run CHKDSK from the Command Prompt:

1. Type “cmd” into the search box. This will launch the Command Prompt.
2. In the new window, type “chkdsk [drive]: /r” where [drive] is the drive letter on which you’re having issues, for example “c”.
3. Windows will scan the drive and work its way through, fixing or correcting errors as it finds them.

Note: “/r” is a command parameter that tells Windows to try and recover info from any bad sectors.

If the error comes from a CD or DVD, the cause might be physical damage to the disc itself. Try cleaning with a soft cloth.

Run System File Checker (Windows)

System File Checker is a built-in Windows utility that will scan files and check for problems using the Disk Image Servicing and Management tool. To run System File Checker:

1. Type “cmd” in the taskbar to launch a Command Prompt window.
2. Type “DISM.exe /Online /Cleanup-image /RestoreHealth” (make sure to leave spaces between the “/”), and press Enter.
   Note: You can choose /ScanHealth rather than /RestoreHealth to simply scan.
3. Once the scanning process is complete you’ll get a message saying “The operation completed successfully.”

4. Next, type in “sfc /scannow” and press Enter.
5. The system will verify the scan.

Note: If you run into an SFC /Scannow error when starting the scan, don’t worry. We have written dedicated articles on what to do if SFC scannow is not working, including:

• Windows Resource Protection Could Not Perform The Requested Operation
• Windows resource protection could not start the repair service

Restore to an Earlier Version (Windows)

This method will rely on your having already created a backup version of your Windows system. If you’ve had the foresight to do that, you may be able to correct the Cyclic Redundancy Check error by restoring an earlier version of your system.

Warning: Version restoring won’t work on a file-by-file basis, so you might lose other file changes and progress, depending on the timing of your backup.

1. Open Windows Settings (Windows Key + I).
2. Click the Update & Security Tile.

3. Click on the Recovery Tile.
4. Choose “Restart Now” from the Advanced startup options.

5. Your PC will reboot. Click the Troubleshoot button when it appears.
6. Click “Advanced Options,” then “System Image Recovery.”
7. The wizard will walk you through the recovery process.

Use the Time Machine feature (Apple)

If you’re using a Mac, you can make use of the Time Machine process to restore the specific document or your whole system to an earlier version. To restore a particular file:

1. Open Time Machine by choosing its icon from the menu bar or by pressing cmd + spacebar and type “Time Machine.”
2. Scroll through the files onscreen to find the specific file you need to revert.
3. Preview by clicking the space bar.
4. Click the Cloud icon to snapshot an image to view.
5. Click “Restore” to restore the file in question.

To restore your entire hard drive (and be careful when choosing this option, as there is a potential to lose other data), you can:

1. Power off your Mac.
2. Turn the Mac back on, holding cmd + R to enter the macOS recovery partition.
3. Once the screen botts to macOS Utilities, click “Restore from Time Machine Backup.”
4. Click “Continue” (or read the information presented).
5. Choose Time Machine backup and click “Continue.”
6. Select your most recent Time Machine backup and click “Continue.”
7. The Mac will now restore the backup to the drive.

Use a Third-Party Recovery Tool

Many tools will assist with data recovery from drives acting erratically, so this might be an option for you if all else fails in your attempt to recover your file or drive. Software programs like Partition Recovery, Stellar Data Recovery, and EaseUS Data Recovery Wizard can scan and recover files from damaged systems. As with all software, you’ll need to do your homework and determine if any third-party tool is right for you and ensure that the software is reputable and legitimate.

Reformat the Drive (Windows)

If your drive is the cause of the issue, it may be possible to correct the problem by reformatting the drive.

Warning: Doing so will erase all of the data on the drive, so this option is a last resort. If possible, copy the contents of the drive to another drive or cloud storage.

1. Open Windows Explorer (Windows Key + E).
2. Right-click the drive in question.
3. Choose “Format” from the window.

4. Choose NTFS for the file format.
5. Check the “Quick Format” box.
6. Click Start.
7. When the process finishes, click “OK” to clear the menu.

Send the Drive for Repair

It might be possible to have a drive repaired by the manufacturer, providing you have time and energy to wait for this process. Some drives may be unrepairable, but the manufacturer will best know how to assess and repair the damage if possible. If you can access the data from the files, always attempt to back up the drive before sending it for repairs.

Conclusion

A cyclic redundancy check data error, when not limited to a single corrupt file, is usually an early sign of a drive that is beginning to fail, so it’s best to take the warning seriously and take immediate action. You may be able to save other data from the drive before it fails completely. Try some of these methods to check where your issue lies, and be proactive about repairing your file or drive in a timely fashion.