How do I decompress the files I download from your site?

files distributed via the Internet were compressed using Windows Zip data compression software. Files compressed using WinZip have the .zip file name extension. Users who download compressed files will have to decompress the files before using them.

Please note that files downloaded prior to November 29, 2004, may have the Gzip compression format.


Windows XP has a built-in decompression tool that decompresses .zip files. Users with other Windows versions may need to download the utility from the WinZip Web site.

WinZip and the Saved Files Utility

WinZip users (and those who use the built-in decompression tool in Windows XP), should be aware that WinZip has two ways to extract files: by using drag-and-drop and by choosing "Extract" from underneath the "Actions" menu. These two methods produce different results. If you use drag-and-drop, then you will only get the files...not the folders that enclose them. Hence you'll lose the hierarchy that has set up (including folders that are titled with study names and dataset names). If you use the "Extract" command from the "Actions" menu, then the folder hierarchy is preserved if 'Use Folder Names' is specified in the extraction dialog box.


For Macintosh OSX users, decompression software is built into the operating system; you can open compressed files by double-clicking on the .zip file.

If you're encountering problems with the MacOSX built-in decompression software, you may wish to download StuffIt Expander.


Users in the UNIX/Linux environment can simply use the unzip command to decompress .zip files.

Once you have the appropriate software on your local machine, follow the instructions supplied by your software to decompress the zipped files.

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