It happens too often. A user downloads a file from one of our Web sites. Soon afterwards we get a message telling us that they tried to open the file in an application and they were told it was corrupt.

First, let me make it clear that there are corrupt files on occasion. Most often from a failed download. But those who complain the loudest need to learn a very basic computer skill, to unzip files.

Let’s quickly go over Zip files. They are a compressed file that could simply make a single file smaller or they could contain multiple files and folders in a single file. Zip files have been around since 1989 so they should be well known to all but the very newest computer users.

Both Windows and Mac operating systems have native functionality to create Zip files and to “unzip” them. Microsoft has a help page explaining how to zip and unzip files. There are also plenty of tutorials for the process on a Mac.

Zip files are very commonly used for downloadable files, though the complaints we receive make it sounds as if we are the only site that offers them. If you attempt to open a Zip file with CorelDRAW, it will fail. Yes, that can be a bit odd since the native CDR file format is a zip in disguise. Trying to open a Zip file in Adobe Illustrator or Adobe Photoshop will also fail. Yes, you’ll often get a message the file is corrupt.

So if you are a person who is unfamiliar with Zip files, I encourage you to learn this very basic computer skill.