You may have encountered the error implying a CRC failed 7 Zip while receiving some files over the internet via email.
As much as it sounds scary, this error is not so uncommon.
What you need to understand here is how and why this error occurs and what exactly does it mean by this failure in a 7 Zip file.
But first off, you need to know what 7 Zip is actually.
What is a 7 Zip file and what is meant by CRC failed 7 Zip?
7 Zip is a very commonly used compression tool, and it is almost similar to the Zip compression tool.
What happens is that as any compression tool does, 7 Zip also compresses various files and their archives in the .7z format. According to experts, this file format is considered a much better alternative to a Zip file format.
7 Zip file format uses various algorithms to shrink all the .7z files and their archives. This format also decompresses several other formats including .rar, .jar, etc.
Now, this 7 Zip file when comes through an email attachment and when the user downloads it to their computer to unzip it, they at times receive a CRC error while trying to extract the contents of the file.
This error is something that makes people really worried because they assume that it is because of some virus or something other than that.
Apart from this particular and special error, these 7 Zip files go through various upheavals so much so that due to various events, their archives get corrupted and start showing different other errors too, that make the 7 Zip file inaccessible for the user.
What is CRC?
It stands for a Cyclic Redundancy Check. It is a type of error code that detects an error in digital networks. This code detects any kind of changes or alterations that may have occurred in raw data form.
Blocks of data that enter this system are given a check value, which is called the CRC value. This value attached with the files is based on the remaining polynomial division of the file archives.
Now, when someone tries to unzip such a file, the applications that are used commonly for decompression, such as WinZip match the evaluated CRC value with the existing value of that file. If these values do not match, that is when this particular error occurs.
Reasons for the occurrence of this error?
This issue that occurs while unzipping or decompressing a 7 Zip file can be caused due to any of the following reasons:
- File alteration due to interrupted transfer of a 7 Zip file: This can be caused due to hacking attempts or some other form of cybersecurity threats.
- An interrupted download of the .7z file: This problem occurs if the downloading of a 7 Zip file over the internet encounters a disturbance or interruption.
- Malfunction of the decompression application: An application like WinZip may be corrupted or malfunctioning and that can also result in this issue showing up.
- Bad storage sectors: Bad sectors in the storage file where a 7 Zip file is stored may also be the cause of this issue.
Regardless of the reason, this issue causes the 7 Zip file to become inaccessible for the users.
Steps to repair the file with this issue:
There are some amazing repair tools available on the internet which can help you to encounter this problem without any trouble. These repair tools can not only fix all the errors that may occur with .7z files, but they also make sure that the repair does not harm the files or their contents in any way.
These tools are made up of such algorithms that are read-only, and they can fix this error in all the versions of Windows easily.
These repair software tools are available for Windows 10, Windows 8/8.1, Windows 7, and below.
All you need to do is:
- Download the repair tool from an authentic site.
- Make sure to download it on the same PC where your 7Zip file has been stored.
- Install this tool on your computer.
- Now, on your display window, you will see the option of Browse.
- Click on it.
- From there, select the file that is showing this problem.
- Once the file is selected, you need to hit the “Repair” button.
- The scanning process will begin. Hold tight and do not interrupt the process in any way. Do not use your computer or try to do any other operations on it.
- The scanning and repair process will take some time.
- After a short while, you will be told that your 7 Zip files have been fixed now.
- You will soon see your repaired file on the display along with all of its contents intact.
- Open this file and see that it has been completely and properly restored and repaired. Then save this file on your computer.
- Make sure that before you download the repair tool, your computer is free of all sorts of viruses and other bugs. It is also better and preferable if your computer is free of all the bugs before you download important files in the .7z format.
- Also, before you start the repair of your 7 Zip files showing this issue, you must make sure that all these file archives have proper backup copies on other external hardware and storage devices.