// Question: 
// How can I read the default language of installed MS Word application? 

// Answer: 
// You may initialize Word.Application instance and read a CountryID: 

var
   word: OLEVariant;
 begin
   word := CreateOLEObject('Word.Application');
   CountryID := word.System.Country;
   word.Quit;
   word := UnAssigned;
 end;

 // After that check this CountryID with next values: 
  wdUS = $00000001;
   wdCanada = $00000002;
   wdLatinAmerica = $00000003;
   wdNetherlands = $0000001F;
   wdFrance = $00000021;
   wdSpain = $00000022;
   wdItaly = $00000027;
   wdUK = $0000002C;
   wdDenmark = $0000002D;
   wdSweden = $0000002E;
   wdNorway = $0000002F;
   wdGermany = $00000031;
   wdPeru = $00000033;
   wdMexico = $00000034;
   wdArgentina = $00000036;
   wdBrazil = $00000037;
   wdChile = $00000038;
   wdVenezuela = $0000003A;
   wdJapan = $00000051;
   wdTaiwan = $00000376;
   wdChina = $00000056;
   wdKorea = $00000052;
   wdFinland = $00000166;
   wdIceland = $00000162;