Language - Outlook Web Access

To switch to interfaces in other languages, In Internet Explorer:

Select Tools ->Internet Options on the menu bar.
In the Internet Options dialog box, select the General tab and click the Languages... button.
In the Language Preference dialog box, click the Move Up button to move your desired language to a higher preference.
You can click also use the Add... button in the Menus and Dialog Boxes dialog box to connect to Microsoft's Web site and install other languages.