Problem:

Program is displaying menu options, fields or grid titles in a language that you do not desire (ie: French vs English or vice versa).

Causes:

If you are using the software in English or French versions there are multiple areas where the Language Localization takes an affect on how the application is run.

Solutions:

To change the language: Go to Utilities > Reset Database Language. This will change the "system language" from English to French or French to English respectively.

Within the program you may discover that money is displayed with a comma (,) instead of a period (.) or vice versa.
French language displays numeric values with non-whole numbers using the comma to represent anything below a whole number.  However, this same information in English is displayed with a period.
Separators at every thousand are represented by a "Space" character in French systems and a comma (,) in English systems.
Therefore

                                           21 500,30 in French  is the same as 21,500.30 in English.

Unlike the Language localization, the settings are assigned to the database when it is created.  Whether to use English or French numbering and date policies is based on the computers "REGIONAL SETTINGS" that sent the command to create the database.  These CANNOT BE CHANGED once the database is created and being used.

How do I change the Regional Settings of my company?

As Said above, you cannot.  Once the database is created the only way to change these settings is create a new company and re-key the information in.  The settings do not change in a database after the database/company has been created.