The new installer of the Live Chat component is modular and only include the necessary things to work. By default they should install 7 languages included : English, Spanish, Portuguese, German, Italian, French and Dutch.
If you want to use a different language on the Live Chat window is necessary to follow the next steps:
1. Download and install the language from the main Joomla download area :
2. Go to the ActiveHelper Dashboard section languages and select the tab "available languages"
3. Select the language from the selection box and and chose the file from.
4. Finally click under the top button "install language"