This is a two stage process you will:

  • Copy all of the Joomla files from your server to your local computer
  • Back up the SQL database using your Cpanel

 

Copying files:

Use your favorite FTP client to copy the Joomla files to your local computer.

The folders (for a default Joomla 1.5 install) will be

Administrator

cache

cgi-bin

components

images

includes

language

libraries

logs

media

modules

plugins

templates

tmp

xmlrpc

The files (for a default Joomla 1.5 install) will be:

CHANGELOG.php

configuration.php

configuration.php-dist

COPYRIGHT.php

CREDITS.php

error_log

htaccess.txt

index.php

INSTALL.php

LICENSE.php

LICENSES.php

robots.txt

Backing up the SQL database:

  • Log in to the Cpanel of your website using http://www.your site name/cpanel
  • Click on phpMyAdmin
  • Select the database for your Joomla install.
  • Click on the export tab
  • Check the "Add drop table" checkbox
  • Under save as file - give the file a name (optional-you can choose the "zipped" radio button...smaller file size)
  • Hit "GO" to create your file and save it to your computer

 

Source/credits: http://www.siteground.com