Files with a ".tgz" or ".tar.gz" extension are compressed archives that users of Unix-based operating systems use to more easily transfer or back up multiple files at once. TGZ files are created by a two-step process that first combines multiple files into a single one ("tar") and then compresses this single file so that it takes up less space ("gzip").
TGZ files perform a similar role as ZIP files that are more familiar to Windows users, but unlike ZIP, Windows does not contain any built-in support for working with TGZ files. If you are transferring files between Windows and Unix computers, however, you may need the ability to create TGZ archives from within Windows.
Download the free and open-source application "7-Zip" by going to their website (see Resources) and clicking the "Download" link for the ".exe" file (if you are running 32-bit Windows) or the ".msi" file (if you are running 64-bit Windows).
Install 7-Zip by double-clicking on the file that you downloaded and following the directions in the wizard that appears.
Select the files in Windows Explorer that you want to add to a TGZ archive.
Right-click on one of the files that you have selected, select "7-Zip" from the menu and then select "Add to archive..."
Enter a new name for the archive in the field labeled "Archive" and then select "Tar" from the "Archive format" drop-down list. Leave the other options set to their default values and click "OK." A file with the extension ".tar" will be created in the current directory.
Right-click on the new ".tar" file, select "7-Zip" from the menu, and then select "Add to archive..."
Select "GZip" from the "Archive format" drop-down list. Leave the other options set to their default values and click "OK." A file with the extension ".tar.gz" will be created in the current directory. This file is the complete TGZ archive.