Internet, Networking, & Security Error Messages CRC Error: What It Is and How to Fix It The cyclic redundancy check error message isn't the end of the world Share Pin Email Print Jane_Kelly/iStock/GettyImagesPlus Error Messages Browsers Cloud Services Error Messages Home Networking 5G Antivirus VPN Web Development Around the Web View More By Brad Stephenson Freelance Contributor Brad Stephenson is a freelance tech and geek culture writer with 12+ years' experience. He writes about Windows 10, Xbox One, and cryptocurrency. our editorial process Facebook Twitter LinkedIn Brad Stephenson Updated July 11, 2019 The cyclic redundancy check (CRC) error message is one that appears when a corruption or suspicious change is detected in data on storage devices and networks. Here's how it appears and how to fix it. How the Cyclic Redundancy Check Error Appears The error is known to appear when a computer is attempting to read data on a local drive, a network drive, an external hard drive, and on disk drives such as those used for reading CDs, DVDs, and Blu-ray disks. The cyclic redundancy check error message typically appears as the following: C:\ is not accessible. Data error (cyclic redundancy check).File ____ could not be accessed. Data error. Cyclic redundancy check.Data error (cyclic redundancy check)Error: Data error (cyclic redundancy check) Causes of the Data Error Cyclic Redundancy Check Error There are numerous situations that could cause a CRC error to appear when using a computer, ranging from the corruption of a file or program registry to file and setting configuration mistakes and faulty app or program installations. A problem with the hard drive can also cause a cyclic redundancy check data error. How to Fix the Cyclic Redundancy Check Error Because the cause of a cyclic redundancy check data error can be related to the file being accessed and the hard drive or disk drive involved, there are a variety of approaches that can be taken to solve this problem. Restart your computer. Yes, it's a bit of a cliché, but this quick and effective process can fix a variety of computer problems, including those associated with data errors. Reconnect external drives. If the error appears while trying to access an external hard drive or disk drive, try unplugging it, restarting your computer, then reconnecting it again. Re-download the file. If you get the CRC error when trying to open or run a file you've downloaded, it's possible the file became corrupted during the download process due to a server or internet connection problem. Downloading the file again can often remove any bugs or glitches you're seeing. Before re-downloading a file, make sure to save it under a different file name so you don't accidentally open the original faulty file again. Request a new copy. If the glitchy file had been sent to you via email, ask the original sender to send you a new copy. The file may not have been attached or uploaded to the email properly. Install the latest operating system updates. New macOS and Windows updates frequently include fixes for drive and file errors and can increase system stability enormously. Scan the drive. You can perform a drive scan on Windows and use Disk Utility's First Aid on macOS to automatically scan your device in the background to detect and correct errors. You only need to perform a scan on the drives that you accessed when the data error occurred. Scan the drive using Command Prompt. If the CRC error is making it difficult to scan the affected drive on a Windows computer via the above method, you can also start a scan by typing "chkdsk /f c:" into the search bar in the Windows taskbar, then select Run command. Make sure to change the 'c' to the correct drive letter. You can also perform a command prompt by typing the above text into Cortana on Windows 10. Try installing from Safe Mode. If you repeatedly get a cyclical redundancy check error when trying to install a program from a disk, try restarting Windows in Safe Mode and attempt installing it from there. After the installation completes in Safe Mode, make sure to restart your computer and run Windows as normal. Format the disk drive. If a hard drive or disk drive is repeatedly giving you trouble, you may need to reformat it. This should be a last resort as it will delete everything currently on the drive. Other Errors Like The Cyclic Redundancy Check Error Error 0x80040116 has been known to appear when saving or copying files from an email client. Its cause is frequently associated with a cyclical redundancy check error and can often be fixed by performing the same tips mentioned above. Similar hard drive and file errors include the "STOP: 0x00000022" and "FILE_SYSTEM" messages that often result in the infamous blue screen of death.