Here are the Microsoft language instructions:

Set the primary language

The primary editing language is the language that you use for most of your work. It is the language for your tools (templates, fonts, font sizes, sorting format, page sizes, bullets and numbering, text direction, etc.), text and number formatting (for example, right-to-left or left-to-right text) for 2007 Office release programs. It does not configure the default language and default dictionary. To configure the default language and dictionary, see Change the default language for Office programs.

1. Click Start, click All Programs, click Microsoft Office, click Microsoft Office Tools, and then click Microsoft Office 2007 Language Settings.
2. Click the Editing Languages tab.
3. In the Primary editing language list, click the language in which you plan to do most of your work.

Important When you change the primary editing language, the Normal.dotm template in Word is automatically replaced. We recommend that you save a copy of Normal.dotm and rename it with its language, for example, Normal_English.dotm, before you change the primary editing language. The Normal.dotm template is typically saved to C:\Users\username\AppData\Roaming\Microsoft\Templates, where username is the name of the person who is logged on to the computer.

Note You cannot remove a language from the Enabled editing languages list if that language is set as the primary editing language. To remove the language from the Enabled editing languages list, you must first select another language in the Primary editing language list, and then remove the language from the Enabled editing languages list.