CRC error: what is it? how to fix
CRC errors can occur on data carriers or specifically when unpacking ZIP or RAR files. Here we show you what a CRC error is and how to fix it.
What is a CRC error?
The abbreviation “CRC” stands for “Ccyclic Redundancy Check” (cyclic redundancy check). CRC is a technology that detects whether data has been accidentally changed in networks and on data carriers. The cause can be a hardware or software defect, making the affected files unusable.
Example: If a compressed archive file is defective, CRC detects any read errors when unpacking and shows a CRC error. The error messages are then something like:
“Drive is not accessible. Data error (CRC check)”“Virtual Media Management. Data error (CRC check).”
Consequence: You cannot access the disk or certain files.
Possible causes of CRC errors
Damaged files or faulty download of files Incorrect program installation Damaged Windows registry Defective data carrier (hard disk, USB stick, DVD, …) Defective virtual data carrier
Fix CRC error
For ZIP or RAR files, open the zipped file with the WinRAR tool. In the menu bar, click “extras” > “Repair archive“.Specifies the location for the repaired archive and whether the archive should be treated as a RAR or ZIP file during repair.Confirm with “OK“.Tries to unpack the repaired archive afterwards. In the best case, no CRC error is displayed anymore.
If the error persists, most of the time not all files in the archive are affected by the CRC error. You can then unpack the still working files as follows:
Open the relevant archive with WinRAR.Click on the button “dep. after” (Extract to). Check the “Keep corrupted files“, selects a more suitable storage location for the files to be unpacked if necessary and confirms with “OK“.In the save location, look at all the unzipped files. The defective files can probably neither be opened nor edited. Disk: Fix CRC errors with CHKDSKRecommendation: Before you repair a faulty disk, it makes sense to back it up in its current state. Because then you can make multiple copies from that backup to perform multiple recovery methods on the raw data without further corrupting the original data. The “AOMEI Backupper Standard” tool, for example, is suitable for this, which, in contrast to “Clonezilla”, can also clone bad sectors. If you absolutely need the data, we recommend going straight to one professional data recovery company instead of trying to repair it yourself. The Windows tool CHKDSK can Fix CRC error. Run at your own risk:Press the Windows + R key combination to open the Run window.Give cmd and press the key combination Ctrl + Shift + Enter. Confirm the message window with “Yes” to open the command prompt with administrator privileges. Type the command chkdsk D: /f /r /x and press Enter. “D:” here stands for the disk on which the CRC error occurred. If the hard disk to be checked is your Windows hard disk, CHKDSK will ask whether the check should be carried out at the next boot because the current drive is not locked can. Then confirm this with “J‘ and Enter. Then restarts Windows.Wait for the CHKDSK process to complete. The process can take several minutes. Even hours on slow hard drives. Windows Disk: Fix CRC errors with DISMPress Windows + R to open the Run window cmd and press the key combination Ctrl + Shift + Enter. Confirm the message window with “Yes” to open Command Prompt with Administrator privileges.Type DISM.exe /Online /Cleanup-image /RestoreHealth and press Enter.After that, type sfc /scannow and press Enter to repair Windows.
CRC error not fixed
If the error has not been corrected, but you absolutely need the data on the data medium, it is best to contact a professional data recovery company. If you don’t absolutely need the data, you can format the faulty disk in Windows to use it again – unless there is a hardware defect.