The languages.xml file explained

[fred]

This is what's in the file:

<languageList>
   <Language>
      <NameEnglish>System</NameEnglish>
      <Name>System</Name>
      <Id></Id>
   </Language>
   <Language>
      <NameEnglish>English</NameEnglish>
      <Name>English</Name>
      <Id>1033</Id>
   </Language>
</LanguageList>

Edit the file with a simple text editor like notepad(.exe)

The languages.xml is located in the folder /lang just below the BoincTasks.exe
These languages are displayed in Extra->Settings->General->Language.

To add an additional language, add the following:

   <Language>
      <NameEnglish>Dutch</NameEnglish>
      <Name>Nederlands</Name>
      <Id>1043</Id>
   </Language>

The language name is displayed in the dropdown list as Nederlands (Dutch).
The id number can be found in Help->Show Log as:

User: 1043 (NLD), System: 1043 (NLD), Used: 1033 (ENU)

User: User selected language.
System: The OS installed language.
Use: The actually selected language.

The language selection sequence is:

1) The selected language.
2) The User language.
3) The System language.
4) The Fallback language 1033 (ENU) = English.

The initial selection is the first item in the list. In this case System = no language selected use User, System or Fallback.

Make sure you use the latest Beta version with the latest text.