User-agent: * 
Disallow: /administrator/
Disallow: /cache/
Disallow: /components/
Disallow: /editor/
Disallow: /help/
Disallow: /includes/
Disallow: /language/
Disallow: /mambots/
Disallow: /media/
Disallow: /modules/
Disallow: /templates/
Disallow: /installation/

#PUT THE FOLLOWING IN YOUR robots.txt file the new stuff is in blue the existing is in black.
User-agent: *
Disallow directory ./
Disallow: /administrator/
Disallow: ./administrator/
Disallow: /cache/
Disallow: ./cache/
Disallow: /components/
Disallow: ./components/
Disallow: /editor/
Disallow: ./editor/
Disallow: /help/
Disallow: ./help/
Disallow: /images/
Disallow: ./images/
Disallow: /includes/
Disallow: ./includes/
Disallow: /language/
Disallow: ./language/
Disallow: /mambots/
Disallow: ./mambots/
Disallow: /media/
Disallow: ./media/
Disallow: /modules/
Disallow: ./modules/
Disallow: /templates/
Disallow: ./templates/
Disallow: /installation/
Disallow: ./editor/