Windows associations
Microsoft has defined the word "associate" as follows:
For example, by default, Windows associates .WRI files with the Write or WordPad application, and .TXT files with the NOTEPAD application. Most Windows application installation procedures create associations. For example, Word for Windows creates an association for .DOC files, while WinZip® generally creates associations for files with the extensions ZIP, LZH, ARJ, ARC, CAB, TAR, TGZ, TAZ, TZ, GZ, Z, UU, UUE, XXE, B64, HQX, BHX, MIM.
WinZip uses associations when you Double Click on a filename listed in the main WinZip window and when you use the CheckOut Feature.
WinZip, My Computer, and Windows Explorer all use associations the same way. When you open a file with an association, the application associated with the file is run, and the application automatically opens the file. WinZip's CheckOut facility establishes associations when it creates the CheckOut window for two reasons: to display the right icon for each file and to ensure that the appropriate application is run when you double click an icon.
You can view, add, and remove Windows associations using My Computer or Windows Explorer. Open My Computer or Windows Explorer and locate Options or Folder Options in the menus (the exact name and menu location depends on your version of Windows). Open the options dialog from the menu and click the File Types tab. Press the F1 key for detailed instructions.
WinZip associations
You can easily review and modify the types of archives with which WinZip is associated from within WinZip. When an archive type is associated with WinZip, Windows will use WinZip to open files of that type.
To view and modify WinZip associations, choose Configuration from the Options menu, click the System tab, and click the Associations button. In the dialog that follows, you will see a list of archive types. You can specify whether an archive type should be associated with WinZip by checking or unchecking the checkbox next to the archive type.