If the file came as a .tar.tar, you must rename it to something.tar.gz — with a .tar.gz extension, not .tar.tar
Then use an unzip program such as WinZip. In such programs you frequently have to go through a few steps to extract the files.
To extract files from a .tar.gz archive using WinZip, follow these steps: 1. Click (or double-click) on the .tar.gz file. This will trigger a popup window asking “Should WinZip decompress it to a temporary file and open it? Click Yes.
2. In the next window, select “Open the archive using the Classic interface.
3. This will bring you to a window with a list of files in it. At the top of the window, click Actions –> Select All.
4. Next click Actions –> Extract
5. In the next screen, browse to where you want to dump the files. We STRONGLY suggest that you choose a folder, then ALSO click the “New folder” icon at the upper right corner of the window. Name your new folder something you will recognize, and write down the location of where you are putting this folder.
6. Now that you have your new folder created, you still have to click on it and make sure the little folder icon appears to be opened up.
7. In the lower part of the window you are in (the “Extract” window), under “Files”, select “All files/folders in archive”
8. In the checkbox choices on the lower right of the window, the only box you should check is “Use folder names”. Click “Extract”. Wait for the little hourglass icon to appear and disappear once or twice — this may take a few seconds if you have a very large backup file.
9. Close the Extract window. You will be presented with a choice: choose “Next time start WinZip with the Wizard interface”.
10. Now you can browse on your computer to where you unzipped your archive. You should see files and folders. The folder containing all your web site files is the public_html folder.