What are Zip files?

Zip files are single files, sometimes called "archives", that contain one or more compressed files. Zip files make it easy to keep related files together and make transporting, e-mailing, downloading and storing data and software faster and more efficient. The Zip format is the most popular compression format used in the Windows environment, and WinZip is the most popular compression utility.

Why do people use Zip files?

Zip files compress data and therefore save time and space and make downloading software and transferring e-mail attachments faster. Typical uses for Zip files include:

• Distributing files on the Internet: Only one download is required to obtain all related files, and file transfer is quicker because the archived files are compressed.
• Sending a group of related files to an associate: When you distribute a collection of files as a single Zip file, you benefit from the file grouping as well as compression.
• Saving disk space: If you have large files that are important but seldom used, such as large data files, simply compress the files into a Zip file and then unzip (or "extract") them only when needed.

Where does WinZip fit in?

To store files in a Zip file, or to access the files in a Zip file, you need a compression utility such as WinZip. WinZip makes it easy for Windows users to work with archives. WinZip features a standard Windows point-and-click drag-and-drop interface for viewing, running, extracting, adding, deleting, and testing files in Zip files. Occasional and first-time users can choose to use the intuitive WinZip Wizard.

How do I open a Zip file?

After you have installed WinZip, you can open a Zip file by double clicking it  and choosing "Unzip or install from an existing Zip file" in the WinZip Wizard. (If the WinZip Wizard does not open by default when you start WinZip, just click the Wizard button in the toolbar). The WinZip Wizard will guide you through the process of unzipping your file.

How do I create a Zip file?

To create a new Zip file, open WinZip in the WinZip Wizard mode. (If the WinZip Wizard does not open by default, just click the Wizard button in the toolbar.) You will be asked "What do you want to do?" Simply select "Create a new Zip file" and click Next. The WinZip Wizard will guide you through the entire process.

When you become more familiar with Zip file operations, you can also try the WinZip Classic interface. The Classic interface offers many advanced features that are not available in the WinZip Wizard. Using the Classic interface, you can split large Zip files into smaller parts to overcome e-mail and other size limits; view, extract, and run individual files in a Zip file; remove files from an existing Zip file; encrypt your confidential files so that they can't be used without a password; and much more. To try the Classic interface, simply click the WinZip Classic button in the WinZip Wizard. Extensive program help is available for every aspect of WinZip Classic operation.

WinZip is tightly integrated with Windows and makes comprehensive use of Windows' drag and drop, desktop, and context menu features. Many WinZip users find that they can accomplish most of their common zip-related tasks without ever opening a WinZip window.

Here are some of the things you can do using drag and drop:

• Compress files and folders by dragging them to a Zip file. It doesn't matter where the Zip file is: it could be open in a WinZip window; it could be listed in an Explorer window; it could be an icon on the desktop; it could even be showing in the Open File listing of an application. It doesn't matter where the files and folders you want to add are, either. If you can see the Zip file and what you want to add to it, just drag and drop, and WinZip does the rest.
• Add files to the archive of your choice by dragging them to the WinZip desktop icon.
• Extract files from a Zip file by dragging them from a WinZip window to the folder of your choice.
• Extract all of the files from a Zip file by dragging it with the right mouse button to a folder or folder icon.
• Open or view files in a Zip file by dragging them from the WinZip window to the appropriate application icon or window.
• Print files from a Zip file by dragging them to a printer or printer icon.

And you can perform the most-needed Zip operations using Explorer context menus, too; just select the items of interest (files, folders, or Zip files), right click, and:

• Add the items to a Zip file. You can choose an automatically named Zip file, a Zip file of your own choosing (including new ones), or you can pick from a list of recently used Zip files.
• Zip and E-Mail the selected items.

If the selected item is a Zip file, you can:

• Extract files. You can extract to the current folder, an automatically named subfolder, any of a list of recently used folders, or any folder of your choice. You can even extract from multiple Zip files in one operation by selecting them all before right-clicking.
• Print a listing of the files contained in the Zip file.
• Convert the Zip file to a self-extracting Zip file.
• Encrypt the Zip file using either AES encryption or standard Zip 2.0 encryption.

A Wizard is a series of panels or pages that help you through a task. The Wizard look and feel is standardized, and is used throughout Windows and in many applications. Wizards are especially useful for complex or infrequently performed tasks.

The WinZip Wizard automates the most common tasks involving Zip files. Using the Wizard, you can:

• Quickly access Zip files you've downloaded: no need to use Windows Explorer to hunt for downloaded files. The Wizard lists the Zip files in your "Favorite Zip Folders" by date, with the most recent files first, so you can quickly access the files you most recently downloaded. A search feature will find any Zip files "lost" on your hard drive.
• Automatically install of software, desktop themes, and screen savers distributed in Zip files: if a Zip file contains a "setup" or "install" program, a desktop theme, or a screen saver, the Wizard will unzip the files, run the installation program (if appropriate), and clean up temporary files.
• Easily zip, and unzip: just check the option for the action you want to perform, and the Wizard leads you through the process, step by step.
• Decode MIME files (such as AOL e-mail attachments) quickly and easily.
• Extract files from split or multiple disk ("spanned") Zip files.
• Run pre-defined WinZip Job Files, or custom Job Files, that are provided to you from a trusted source.

WinZip Wizard vs. WinZip Classic Interface

Both the WinZip Classic and Wizard interfaces are included in all versions of WinZip. One click switches from the Wizard to the Classic interface and vice versa.

• The WinZip Wizard interface is ideal if you want to know as little about Zip files as possible and just get started with the files you've downloaded. The Wizard lets you click the "Next" button a few times, and presto, your files are zipped, unzipped, or installed. When you want to use more advanced zipping features, you can easily switch to the Classic interface.
• The award-winning WinZip Classic interface, featuring tight integration with the Windows shell and versatile drag-and-drop facilities, is great if you are comfortable using Windows and Windows Explorer or if you want to use advanced zipping features.

If you are using Outlook 2000, Outlook 2002 or Outlook 2003 (but not Outlook Express), the WinZip Companion for Outlook provides an easy way to compress attachments while you are composing or sending messages in Outlook. The Companion can:

• compress attachments individually as you insert them
• ask you whether or not you want them zipped, or
• compress all attachments into one Zip file, automatically, when you send your e-mail.

The Companion makes it easy to zip your e-mail attachments, saving transmission time and disk space for both the sender and receiver. And, if your attachments are sensitive, you can easily protect them with advanced AES encryption.

How to compress and attach files or folders from My Computer or Windows Explorer

To compress files or folders and attach them to a new e-mail message from My Computer or Windows Explorer, simply right-click on the files or folders and choose Zip and E-Mail from the context menu. WinZip will compress the selected items to a temporary Zip file, create a new e-mail message, and attach the Zip file to it. You can then address and mail the message as you normally would. WinZip will automatically delete the temporary Zip file when it is no longer needed.

Additional WinZip Features?

Online Help

WinZip makes it easier than ever for you to find the WinZip information you need by presenting help information using the newer Microsoft "HTML Help" facility. HTML Help has a more attractive appearance and includes many usability improvements.

• WinZip can open "skin" files for Microsoft Media Player 7 (.WMZ), Yahoo! Player (.YFS), and WinAmp (.WSZ). Once open, you can use most of the operations available with any Zip file.
• WinZip can display Zip file comments of up to 64,000 characters if your system provides the necessary "rich edit" control.
• Support for filenames containing multi-byte character set (MBCS) characters used with Asian languages such as Japanese, Chinese, and Korean has been improved.
• The limit on the number of entries created by the CheckOut feature in the Programs menu has been increased from 50 to 500.
• WinZip removes from the list of recently used files any files that no longer exist and were opened from the temporary or Internet files folders. This means that, for example, Zip files opened from your e-mail program no longer appear in your recently used file list after they have been deleted by the e-mail program.
• Additional miscellaneous improvements to the WinZip program and help files.

• With Fast User Switching, another user can log on and perform other operations (including using WinZip) while a long WinZip operation is being performed.
• WinZip's Favorite Zip Folders feature now monitors more folders, including Windows XP's "Shared Documents" folder and its subfolders, making it easier to find Zip files created or stored by other users.

A self-extracting Zip file is an executable file (.exe) that contains a Zip file and a small program to extract (unzip) the contents of the Zip file. Users can run (execute) a self-extracting Zip file just as they run any other program: just double click on the .exe file.

What are the Advantages to Self-Extracting Zip Files?

• Self-extracting Zip files are ideal for electronic file distribution because they:
  • Optionally run a "setup" or "installation" program, which may be included by the developer when the files are decompressed.
  • Provide easy distribution of one or more compressed files.
  • Can contain multiple compressed files, minimizing download time and ensuring that important files do not become separated from the rest of the package.
  • Allow the receiver to use a familiar Windows interface to extract (unzip) files, without owning or knowing how to use a separate unzip utility, making them ideal for inexperienced users.
• Any folder information in the Zip file is automatically restored, including empty folders.
• You can create self-extracting Zip files that both unzip and overwrite automatically.
• Self-extracting Zip files are 100% compatible with the Zip 2.0 standard.
• When a self-extracting Zip file created by WinZip Self-Extractor is run, a dialog box is displayed. This dialog box makes it easy for the user to change the "Unzip To" folder and other options before extracting the files.

You can use the technique described here to compress attachments while composing messages using Outlook, Eudora, Netscape Mail, and other programs that allow you to attach files using the standard Windows "File Open" dialog box. This technique does not require a MAPI-compatible e-mail program.

1. Open the dialog box you normally use to attach files:
   • In Outlook: choose File from the Insert menu.
   • In Eudora: choose Attach File from the Message menu.
   • In Netscape: choose Attach and then File from the File menu.
   • In AOL: click the Attachments, then the Attach buttons.
2. Using the standard Open File dialog box, locate the file you wish to attach.
3. Position the mouse pointer over the filename in the dialog box, then click the right mouse button and choose Add to filename.zip from the context menu (note: the filename shown in the menu entry will be the same name as the file you selected). This will create a new Zip file with the same name as the file you selected; for example, it would create Budget01.zip from Budget01.xls.
4. Click once on the name of the new Zip file to select it. This file will normally be at the end of the current directory listing.
5. Click the Open or Insert button to attach the Zip file. You can delete the Zip file after attaching it.

Note: this technique has been tested with Outlook 97, Outlook 98, Outlook 2000, Outlook 2002, Outlook 2003 and Outlook Express; Eudora 3.0, Eudora 4.0 and Eudora 5.0; the mail program in AOL 4.0, AOL 5.0, AOL 6.0, AOL 7.0, AOL 8.0, and AOL 9.0; and the Netscape 4.0 mail client.

Some types of files compress better than others.For example, various multimedia files are already highly compressed because the standards for these file types specify efficient techniques to compress the data they contain. Examples include files in the graphics (picture) file formats GIF and JPG, MP3 music files, and MPG movie files. Once a file has been compressed, it typically can't be compressed again to any significant extent. Therefore, such files don't get very much smaller when they are added to a Zip file.

You would see similar results if you compressed some files into a Zip file using maximum compression, and then compressed that Zip file into another Zip file. The second archive would not be appreciably smaller than the first one (it might even be a little bigger). This is because the data in the original Zip file is already compressed and can't be compressed again.

There are other file types that don't compress well. For example, certain types of encrypted data files such as those maintained by home finance programs and some database products can't be compressed very much.

By contrast, some types of data (such as text files and picture files in the BMP format that the Microsoft Paint program uses) can often be compressed by 90% or more; some types (such as program files) are often compressed by 50% or so. But if you see files that can't be significantly compressed, it's probably because they already contain compressed data or they are encrypted.

WinZip Command Line Support Add-On