The system locale is also referred to as the system default locale. It determines which ANSI and OEM code pages, as well as bitmap font files, are used as defaults for the system. The system locale contains the language setting, which determines the language in which text appears in the user interface, including in dialog boxes and error messages. A message catalog file defines the language in which messages display. By default, the machine uses the language specified for the system locale for all processes, unless you override the language for a specific process.
The system locale is already set on your system and you may not need to change settings to run Informatica. If you do need to configure the system locale, you configure the locale on a Windows machine in the Regional Options dialog box. On UNIX, you specify the locale in the LANG environment variable.