In this section I will show you how to compress (shrink) and decompress (expand) files using Windows 7 as well as explain how compression and decompression work (in an easy, yoingco, way of course!). On top of this I tested 11 File Compression Utilities to see how well Windows 7 would compare against their file compression rates - The Windows 7 results might surprise you! and lead you to question "Do I really need a File Compression Utility?".

A File Compression Utility, also known as File Archiver, is a program that can normally shrink (compress) one or more regular files into one smaller, compressed/shrunk, file depending on the File Compression Format it uses (see ZIP below). File compression is ideal when you want to e-mail someone ten 1 MegaByte photograph files for example but do not want to e-mail them one photograph at a time. By compressing (shrinking) the ten photograph files (10 MegaBytes) into one compressed file, of 8 MegaBytes for example, you then only need to e-mail that one smaller compressed file.

Fig 1.0  5 assorted files compressed into 1 ZIP formatted file - Would you e-mail the 5 assorted files or just the 1 ZIP formatted file?

Storage is another reason to use file compression. Instead of copying/storing ten photograph files you barely use, but definitely need, onto your hard drive you could always compress them beforehand (i.e. on your Flash Drive) and then only copy/store the compressed file (i.e. from your Flash Drive) onto your hard drive. That way you only have one compressed file, which contains the ten photograph files, stored on your hard as opposed to ten photograph files and one compressed file being stored on your hard drive.

Whenever you need to use those ten photograph files you can simply Decompress (Expand) the compressed file, using the file compression utility, onto your hard drive so that you then have one compressed file and ten photograph files on your hard drive - Compression and Decompression examples using Windows 7 given below.

Fig 1.1  1 ZIP formatted file decompressed into 5 assorted files

ZIP is currently the most popular (standard) File Compression Format around, but there are many other file compression formats in use (7Z, ARC, ACE, CAB, ISO, LHA, RAR, TGZ and so on). ZIP is only more popular because it is supported by Microsoft Windows and MAC OS X, as well as third party software vendors, but it does not mean it is the best file compression format though. Other file compression formats can compress files a lot better than ZIP can but it is due to ZIP being "The Standard" format that many people do not entertain the other formats, even though many of the File Compression Utilities out there do support the other formats.

Just as Microsoft Office 2007 has its own file format for WORD data and its own file format for EXCEL data the same applies to file compression. The file compression utility has the job of formatting (laying out/assembling/archiving) the data from a copy of your original files (i.e. original photograph files) before that copy data is then compressed. This means your original files are left intact/untouched and you end up with a compressed file that is created from a copy of your original files. So the data from two .jpg (photograph) files for example will be formatted and then compressed in exactly the same way, whereas a .jpg file and a .mp3 (music) file will be formatted and then compressed differently from one another.

The table above shows the file compression results from a mixture of ten file compression utilities (7-Zip to ZipGenius) as well as the file compression results from Windows 7. Each file compression utility compressed the files using the ZIP file compression format (results on the left) and where possible in their native file compression format (results on the right). For example. The 7-ZIP file compression utility compressed 8 DOCX (Microsoft Word 2007) files from 1.17 MB down to 1.14 MB using the ZIP file compression format but down to 1.12 MB using its native 7z file compression format. As you can see, in bold, 7-ZIP did very well with its native file format but averaged with the ZIP file format.

The ten file compression utilities are either Free-To-Use, Commercial (Priced) or have a Trial (Test) Period associated with them.

I began by creating 8 .docx (Word 2007) files, 8 .xlsx (Excel 2007) files, 8 .jpg (Photo) files and so on, putting each set of 8 files into their own folder. The exception to this was the .reg (Registry) file which was a separate file of 119 MB. After that I started compressing each folder in turn with the ZIP file compression format, each folder containing its 8 respective files of course, using one installed file compression utility at a time.

Each file compression utility was associated with (set as) the default handler for compression. Where a file compression utility had support for its own file compression format I also compressed the folders using that file compression format. The results of this are shown with the numbers to the right of a forward slash (i.e. 1.14 / 1.12 for 7-Zip). The .reg file was compressed as a file only (not put into a folder). Lastly. I compressed all of the folders and the .reg file together to produce the ALL result.

Surprisingly. NO!.....not all the time. As you can see from the above results Windows 7 matched the average/standard file compression on seven out of the nine file compression tests. Namely the DOCX (Word 2007), XLSX (Excel 2007), JPG (Photo), PNG (Photo), MP3 (Music), PDF (Adobe Reader) and UFO (PhotoImpact Paint Package) file compression tests. This is mainly due to the fact that many of the file formats tested are already classed as compressed file formats. For example. JPG is a compressed file format, as is the PNG file format, so many file compression utilities cannot better their compression rates. So why use a file compression utility at all then?

A file compression utility cannot be judged on its file compression alone. You also have to consider what it can do for you in terms of its User Interface (windows, buttons, menus and so on). Windows 7 does not have a user interface for its file de/compression procedures, one reason why you might consider using/buying a file compression utility. Here are some of the features to look for in a file compression utility and some of the questions to ask about it.

Normally the smaller the file compression size the better, but not always. Why? Because when you come to decompress a compressed file that has been tightly compressed (compacted) it may take longer than normal to decompress it. Therefore, you need a file compression utility that gets the compression balance right.

Now you have an idea of file compression it is time for an example using Windows 7. In the following example I have five files in my DOWNLOADS folder ready to be compressed using the ZIP file compression format. They represent five files that could have been downloaded from the internet, or from an e-mail attachment, that I now want to compress. I could compress them for storage purposes (i.e. delete the five files, once compressed, and store the ZIP file only) and also e-mail someone the ZIP file later - Two normal reasons for wanting to compress the five files.

With a file compression utility you can select from different devices and folders (i.e. Flash Drive folder, CD Drive, etc) the folders and files you want compressing, but not with Windows 7. It only allows folders and files to be compressed from one folder (or sub-folder). Therefore. If you have not done so already, make sure the files you want compressing are all in the same folder (or sub-folder).

Begin by selecting (left clicking on) the folder(s) and/or file(s) you want compressing. Any folder you select will automatically have its content (sub-folders and files) included in the compression. From there. Right click over a selected file (or folder) to bring up the Options menu (Fig 2.0 below) and then move the mouse pointer over to the SEND TO sub-menu, but do not click on it. As the mouse pointer hovers over the SEND TO sub-menu its menu-items will appear. You need to left click on the COMPRESSED (ZIPPED) FOLDER menu-item in order to create a compressed ZIP file - Microsoft correctly calls it a Compressed ZIP Folder because it places your compressed folders and files inside a folder of its own, but this is generally known as a ZIP file or ZIP archive.

Fig 2.0  Click on the COMPRESSED (ZIPPED) FOLDER menu-item in order to create a compressed ZIP file

In the above example I have selected the five assorted files. When I click on the COMPRESSED (ZIPPED) FOLDER menu-item Windows 7 will begin compressing a copy of those files, using the ZIP file compression format, to produce one ZIP file inside my DOWNLOADS folder. The original five files will be left untouched/intact.

Once the ZIP file has been created (Fig 2.2 below) its filename will be selected, in an editable state, so that you can rename the ZIP file. The renaming process is exactly the same as renaming a folder and renaming a file. Therefore. If you do not want to rename the ZIP file simply click anywhere within the display area (white space) of the folder's window to deselect the ZIP file and set/keep its given file name. Its given name is taken from the name of the file, or folder, you right click over to bring up the Options menu (Manual.pdf in Fig 2.0 above), but can also be taken from the last selected file if you use the FILE menu, SEND TO sub-menu instead of right clicking over a file.

Fig 2.1  Compressing, a copy of, the five files into one ZIP formatted file



Fig 2.2  The ZIP file has taken the name Manual, from the Manual.pdf file which was right clicked over (Fig 2.0 above).

Remember. A ZIP file is created from a copy of your selected (original) files which are left untouched/intact. Therefore. When a ZIP file is created you could delete your original files, store them elsewhere or just leave them where they are. And the same applies to the ZIP file. You could e-mail it to someone, delete it afterwards, store it somewhere without e-mailing it and so on. It all depends on what you want to achieve with the created ZIP file.

In this next example I have just downloaded a ZIP file, called Photos.zip, from an e-mail attachment into my DOWNLOADS folder and now want to unzip (decompress/expand/extract) it. All that is needed here is to right click over the ZIP file, to bring up the Options menu, and then select (left click on) the EXTRACT ALL menu-item. This in turn will bring up the Extraction Wizard that will guide me through the extraction (decompression/expansion) process.

Fig 3.0  Right click over a ZIP file and then select the EXTRACT ALL menu-item to continue



Fig 3.1  Click on the EXTRACT button to continue

The first window of the extraction wizard displays the Destination folder of where the ZIP file content (contained/compressed folders and files) will be stored. Currently in the same folder as the ZIP file (the DOWNLOADS folder) but within its own folder - The folder that was created when it was zipped (compressed) using the SEND TO >> COMPRESSED (ZIPPED) FOLDER menu-item. So in this example the ZIP file content will be stored inside the DOWNLOADS folder but within its own folder (sub-folder) called Photos. To change this destination folder I would simply click on the BROWSE button to bring up the Select A Destination folder requester and then navigate it to my preferred folder. In this example though I will keep the Photos folder (sub-folder) as the destination folder and just click on the EXTRACT button to continue.

The tick next to SHOW EXTRACTED FILES WHEN COMPLETE means open the destination folder, if it is not already open, when the zipped (compressed) files have been extracted (compressed/expanded). And if the destination folder is already open make it the front-most folder (window) by bringing it to the front of all other folders (windows).

Fig 3.2  Decompressing (extracting/expanding) the ZIP file into 25 files



Fig 3.3  The opened, front-most, destination folder (Photos) displaying the 25 decompressed files.

As you can see. Compressing and Decompressing folders and files using Windows 7 is not hard work. It is just the terminology that tends to get in the way. Regardless if you use Compress, Shrink, Crunch or ZIP you should be understood and the same applies to Decompress, Extract, Expand and UnZip.

If you want to see what is inside a compressed file before decompressing it simply double click on the compressed (.zip) file, and then on any sub-folder if need be, to view its content. From there you can double click on a file to open it, if Windows 7 supports this action with a particular file type.

Fig 3.4  Double click on a compressed (.zip) file to view its content - From there you can double click on a file to open it.

As said above. File Compression Utilities offer a wide range of User Interface (windows, buttons, menus and so on) features not found with Windows 7 file compression. However. If you only occasionally need to UnZip (decompress/extract) files that belong to an e-mail attachment or a downloadable zip file for example Windows 7 is capable. And the same applies if you only need to Zip (compress/shrink) a few folders and files.

The downside of many file compression utilities, even some of the best ones, is that they tend to be over-featured and too complex for the absolute beginner. Most, if not all, can use the SEND TO >> COMPRESSED (ZIPPED) FOLDER menu-item but for more featured, user interface based, tasks their complexities outweigh their general usage. In other words. You might never use some of their more complex, but common, features. Hence why I stated at the beginning of this section that you might ask yourself "Do I really need a File Compression Utility?".

Microsoft product screen shot(s) reprinted with permission from Microsoft Corporation.  As stated here by the Microsoft Corporation.