How to use file extraction to save disk space

By: Don Edrington - North County Times | Sunday, March 5, 2006 8:11 PM PST ∞

A number of readers have questioned the meaning of the "ZIP" extension on files they download, along with expressing concern about a message saying "Your files are being extracted."

"Zip" refers to "compressing" files so they use less disk space and can be uploaded and downloaded faster. A ZIP extension means that one or more files have been shrunk to a single "zipped" file, which will need to be "unzipped" (decompressed) before its contents can be used. (This is like removing moisture from "dehydrated foods," so that their containers can be smaller and lighter, but which need water replaced to be useable.)

In WinXP, a zipped file can be decompressed by double-clicking it, whereupon you may see "Your files are being extracted." With earlier versions of Windows a program such as WinZip is needed (available from www.download.com).

The unzipped contents of a zipped download may be a single file, or a group of files (such as an assortment of songs), or a collection of files that will be combined into a working program when the "setup.exe" file is run.

Although a zipped file is usually thought of as something that is downloaded, most files can be compressed. For instance, I just squeezed an 894KB MSWord file down to 115KB, meaning the zipped file's size is about 13 percent of the original.

I just as easily could have selected a group of files, or a folder full of files, and done the same.

Here's how: right-click the selected file(s) and choose Send To>Compressed (zipped) Folder. To later open the zipped folder and return the contents to their previous state, simply double-click it.

Nowadays with huge hard drives and high-speed online connections, we rarely think about shrinking files. Nonetheless, if you want to back up some data on a floppy disk or a CD, you'll get a lot more on it by first zipping the files.

Some files are normally compressed to begin with and don't lend themselves well to being zipped, such as JPG images. (More about this can be found on my Web site.) In any case, zipping files in no way hurts them because it's all done with copies of the files. In fact, zipping files to conserve disk space does just the opposite if you leave the zipped and original files on the same disk.

As for downloading zipped files, be aware that malicious hackers often use them to carry deadly viruses. Do NOT open an e-mail attachment with a ZIP extension unless you are expecting it and are absolutely sure of its origin.

A reader called to say she scanned some government forms (using Optical Character Recognition) into MSWord, but could not get the scanned pages to line up properly for typing in her name and address, etc.

Right, this doesn't work. However, most forms are now available as downloads that are designed to be filled in on a PC. For instance, income tax forms are available at www.irs.gov, where you can type in a brief description of the needed form.

More tips can be found at www.pcdon.com and calls are welcome at (949) 646-8615.