Language Packs for Autodesk Inventor 2014 and LT are not on the product media. They are available via download. Access Language Packs for Autodesk Inventor 2014 from http://www.autodesk.com/inventor-languagepacks
Each language pack installer creates a shortcut in the Start menu with the language appended to the product name, such as "Inventor - German (Deutsche)". You can click this shortcut to start the product in the specified language.
The Target line of the Start Menu shortcut specifies the language switch.